Kinematic and dynamic modelling for a class of hybrid robots composed of m local closed-loop linkages appended to an n-link serial manipulator

Recently, more and more hybrid robots have been designed to meet the increasing demand for a wide spectrum of applications. However, development of a general and systematic method for kinematic design and dynamic analysis for hybrid robots is rare. Most publications deal with the kinematic and dynamic issues for individual hybrid robots rather than any generalization. Hence, in this paper, we present a novel method for kinematic and dynamic modelling for a class of hybrid robots. First, a generic scheme for the kinematic design of a general hybrid robot mechanism is proposed. In this manner, the kinematic equation and the constraint equations for the robot class are derived in a generalized case. Second, in order to simplify the dynamic modelling and analysis of the complex hybrid robots, a Lemma about the analytical relationship among the generalized velocities of a hybrid robot system is proven in a generalized case as well. Last, examples of the kinematic and dynamic modelling of a newly designed hybrid robot are presented to demonstrate and validate the proposed method

Context-aware Knowledge-based Systems: A Literature Review

Context awareness systems, a subcategory of intelligent systems, are concerned with suggesting relevant products/services to users' situations as smart services. One key element for improving smart services’ quality is to organize and manipulate contextual data in an appropriate manner to facilitate knowledge generation from these data. In this light, a knowledge-based approach, can be used as a key component in context-aware systems. Context awareness and knowledge-based systems, in fact, have been gaining prominence in their respective domains for decades. However, few studies have focused on how to reconcile the two fields to maximize the benefits of each field. For this reason, the objective of this paper is to present a literature review of how context-aware systems, with a focus on the knowledge-based approach, have recently been conceptualized to promote further research in this area. In the end, the implications and current challenges of the study will be discussed

The effect green YF3:ER3+,YB3+ phosphor on luminous flux and color quality of multi-chip white light-emitting diodes

The purpose of this paper is to demonstrate the advantages of the green phosphor YF3:Er3+,Yb3+ combined with multi-chip package to the enhancement of lighting efficiency of modern WLEDs. In an effort to improve the quality of WLEDs and create a new generation of lighting device, green phosphor YF3:Er3+,Yb3+ is added into the phosphor compounding of the WLED package to improve the color quality and lighting capacity. Through experiments, WLEDs with YF3:Er3+,Yb3+ green phosphor has shown improved results in lighting performance specifically in color homogeneity and light output of WLEDs in the ACCT range from 5600-7000 K. However, the color quality scale (CQS) declines gradually. Therefore, if the appropriate concentration and size of YF3:Er3+,Yb3+ are determined, the performance of MCW-LEDs will be enhanced and become more stable

The Impact of Personal Financial Literacy on the Choice of Lending Channel by Vietnamese Householders Who Just Escaped Poverty

Purpose: The Newly-Escaped-Poverty-List householders (NEPLH) in Vietnam served as the survey subjects for this study, which sought to determine the impact of "Personal Financial Literacy" on "The Probability of Using Lending Services of Vietnam Bank for Social Policies (P_VBSP)" and "The Probability of Using Informal Private Lending Services (P_ILC)".   Design/methodology/approach: Survey data were collected from 186 respondents, by structured online questionnaire with convenient non-probability sampling technique.  Aspects of personal financial literacy (FLi) such as personal financial knowledge (FL1), personal financial skills (FL2), personal financial attitude (FL3), and personal financial behavior (FL4) are measured. When respondents were divided into groups based on subgroup criteria (CVj), such as gender, age, marital status, role in the family, career, education level, religion, and number of years since being removed from the list of poor households, ANOVA techniques were used to examine differences in various aspects of personal financial literacy. The impact of FLi and subgroup variables (CVj) on P_VBSP and P_ILC was assessed using the binary logistic regression analysis technique.   Findings: Research results show that  there is a statistical difference in the average score of FL1, FL2, FL3 and FL4. The research findings also show that FL2, FL4, and "Career Status – CAR" have a positive impact on P_VBSP, while "Aged group - AGE", "Education level - EDU", and "Number of years since being removed from the list of poor households - YEAR" have a negative impact on P_VBSP. Meanwhile, the P_ILC is positive influenced by the AGE factor and moves in the opposite direction of FL2, FL4, EDU, and YEAR.   Research, Practical & Social implications: The research findings provide the basis for governance implications as well as policy recommendations to promote financial literacy among the NEPLH in Vietnam, encouraging them access policy lending services from the Vietnam Bank for Social Policies, and at the same time help them stay away from informal private lending services, thereby helping them to reduce poverty and achieve sustainable economic development family.   Originality/value: A theoretical framework for personal finance literacy, including (i) financial knowledge, (ii) financial attitude, (iii) financial skills, and (iv) financial behavior, has been developed by the authors after reviewing earlier studies. At the same time, it is more significant to measure financial literacy by objective assessment than relying on the subjective self-assessment of each respondent in the context of actual study in Vietnam. In the model analyzing the influence of personal financial literacy on the decision of Newly-Escaped-Poverty-List householders in choosing the Vietnam Bank for Social Policies or Informal Private Credit Channels, the authors also took into account additional factors including gender, age group, marital status, role in the family, career, education level, religion, and number of years since being removed from the list of poor households

A novel mathematical approach for finite element formulation of flexible robot dynamics

In conventional Finite Element – Lagrangian methods, the dynamics model of a flexible robot is usually formulated based on a critical assumption that the kinetic energy of an element is approximately calculated with an integral of mass point energy. Since the energy integral is implicit, the formulation of the dynamics model is also very complex and implicit. Hence, this paper develops a new mathematical approach for the dynamic modelling of a general flexible/rigid robot. The proposed method is more comprehensive and efficient in comparison with the previous ones because it no longer requires the calculation of the symbolic integrals and the implicit expressions of the elemental and global mass matrices. Besides, the proposed approach is applicable for both the flexible robots and the hybrid flexible/rigid robots. To validate the proposed method, numerical simulations and experimental results are presented

Factors affecting the creativity of high school students

Creativity is a vital personality quality of each individual. Each person has their potential for creativity, and it can be nurtured and developed in an appropriate and safe environment. The purpose of the study was to find out which factors from schools and students themselves affect creativity as well as the association between creativity and age, gender and giftedness of students, which then a basis to adjust and establish appropriate methods from schools, families, and students themselves to develop elements and their creativity. The study was conducted on 108 high school students in three grades from giftedness and non-giftedness schools. The data was collected through a survey method using a self-constructed questionnaire and drawing creativity test TCT-DP to determine students' creativity levels and personal information. The study's finding, which uses mathematical methods and one-way analysis of variance, reveals that factors affecting elements and creativity level are objective factors including education environment from school; behavior of teachers, and subjective factors including interests, perspectives, and thoughts of students. It was also found that there were no significant differences in the components of creativity and creativity among students in different grades, gender, and groups of giftedness schools

THE RELATIONSHIPS BETWEEN STUDENTS’ SELF-CONFIDENCE AND THEIR ENGLISH-SPEAKING PERFORMANCE: A CASE STUDY OF ENGLISH-MAJORED STUDENTS AT A PRIVATE UNIVERSITY IN VIETNAM

This research aimed to discover the relationships between students' self-confidence and their English-speaking performance. In our research, self-confidence was divided into three components which are affective confidence, behavioral confidence, and cognitive confidence. In addition, speaking performance included eight components which are vocabulary, grammar, pronunciation, fluency, coherence, comprehension, task, and content. A sample of 150 English-majored students at a university in Vietnam was surveyed in this study by using a convenience sampling technique, and then conducting semi-structured interviews to seek for qualitative information from 10 participants out of 150. The result from our study showed that there are significant relationships between the two variables. The more confident the students are, the more accomplished they would be in the presenting procedure since they have superior cognition and understand how to modify their learning methods to build a comprehensive individual in learning English language. We expect that these findings can help students adjust their learning methods to improve their self-confidence as well as English speaking performance and by that way, universities can add more speaking-related subjects so that students can have more opportunities to speak and learn more speaking skills.  Article visualizations

Antibacterial Nanocomposites Based on Fe 3

For the vulcanized natural rubber (NR), incorporation of silver nanoparticles (AgNPs) into the NR matrix did not exhibit the bactericidal property against Escherichia coli (E. coli). However, incorporation of AgNPs into polyethylene (PE) matrix showed good antibacterial activities to both Gram-negative and Gram-positive bacteria. In the present work, NR/PE (85/15) blends have been prepared by melt blending with presence of compatibilizer in an internal mixer. To possess antibacterial property, AgNPs (5–10 nm) or Fe3O4–Ag hybrid nanoparticles (FAgNPs, 8 nm/16 nm) were added into PE matrix before its blending with NR component. The tensile test indicated that the presence of compatibilizer in NR/PE blend significantly enhanced the tensile strength and elongation at break (up to 35% and 38% increases, resp.). The antibacterial activity test was performed by monitoring of the bacterial lag-log growth phases with the presence of nanocomposites in the E. coli cell culture reactor. The antibacterial test showed that the presence of FAgNPs in NR/PE blend had a better antibacterial activity than that obtained with the lone AgNPs. Two similar reasons were proposed: (i) the faster Ag+ release rate from the Fe3O4–Ag hybrid nanoparticles due to the electron transfer from AgNP to Fe3O4 nanoparticle and (ii) the fact that the ionization of AgNPs in hybrid nanostructure might be accelerated by Fe3+ ions

Empowering Vietnamese EFL Learners at Tertiary Level: Investigating Factors Shaping Learner Autonomy in English Language Acquisition

This study scrutinizes the viewpoints of Vietnamese students studying English as a Foreign Language (EFL) regarding determinants impacting their autonomy in English language acquisition. Data was amassed from 117 Vietnamese EFL learners attending a university in Vietnam by using a survey-based methodology. The survey instrument, comprising Likert-type items, was predicated on well-established conceptual frameworks derived from antecedent studies. The study unveiled multiple key influences on learner autonomy, incorporating voluntariness, learner choice, adaptability in study alternatives, peer collaboration, and beliefs about the educator’s role, motivation, capabilities, and independence. These determinants underscore the significance of learners’ active participation, personal agency, social interactions, nurturing learning ecosystems, intrinsic motivation, efficacious learning strategies, and learner empowerment in cultivating learner autonomy. The implications gleaned from these results emphasize the necessity for pedagogical stratagems that encourage voluntariness, learner choice, peer collaboration, teacher backing, motivation, skill enhancement, and learner agency within English language educational environments. These pedagogical stratagems would better equip learners for the autonomous journey of English language acquisition, thereby enhancing the overall efficiency of English language education in the Vietnamese context