STUDENTS’ ERRORS IN SOLVING MATHEMATICAL WORD PROBLEMS AND THEIR ABILITY IN IDENTIFYING ERRORS IN WRONG SOLUTIONS

Solving mathematical word problems is a difficult, complex and intellectual activity. The formation of problem solving skills is much more difficult than calculation skills because the problems are related to many concepts and a lot of mathematical relationships. Therefore, students are inevitable to commit errors to deal with them. This study shows the errors of 160 3rd grade students regarding some kinds of word problems in Mathematics 3 in Vietnam. The results indicate that children commit many errors due to many different reasons such as: subjectivity, carelessness, wrong application of the calculation rules, incorrect identification of problem kinds and wrong calculation.  Article visualizations

Study of interference fit between steel and brass parts

Interference fits are generally used in mechanical systems because they have low-cost production and their assembly parts are much smaller than other mechanical joints. Also, their geometric shapes and material properties allow technicians to actively determine how strong the fits are. In this study, let’s present research on interference fits between steel and brass assembly parts. The experimental processes were accomplished with five pairs of specimens to evaluate the behaviours of surface asperities under a high loading condition. Specifically, the specimen pair includes a C45 steel shaft and a C2680 brass hub, which have different surface roughness values (Ra). Let’s apply high-precision methods in measuring all dimensional parameters and employed axial load tests for distinctively inspecting the steel-brass interference fit performance. In every experiment, the measured responses are: 1) the surface roughness values (Ra) before and after loading cycles; 2) the axial load (Fa); 3) the relative displacement value or the real-time interface length in loading stages (l). The aim of this study is to propose a new relative interference value specifically between steel and brass assembly parts, which can help determine the interference loss value more accurately. It was not concluded that with the relative interference of 2.25 ‰ the load capability of steel-brass interference fits is extended. Besides, let’s narrow down the predictive loss coefficient (a) for steel-brass interference assemblies ranging from 1.1 to 2.1, which varies from widely used standards considering a=3. This result helps minimize inaccuracies in interference fit designs, calculations, and work capabilities

Optimization of technological parameters in ultrasonic welding of the polypropylene fabric using Taguchi and FCCCD methods

Ultrasonic welding is a welding method that has been applied for welding nonwoven fabrics, with many advantages such as fast speed, high reliability, easy automation and especially less pollution to the environment. This paper studies the optimization of technological parameters in the welding process such as welding time, pressure, and weld shape on the breaking strength of ultrasonic welding of Polypropylene (PP) nonwovens. To evaluate the influence level and find the reasonable technological parameters domain in the paper, the Taguchi method is used in combination with the face-centered central composite design (FCCCD) response surface method. The research results have determined the regression equations used to calculate the breaking strength for each weld shape as well as the optimal domain for the main technological parameters, ensuring the breaking strength of the weld. There are different degrees of influence of technological parameters (shape of the weld zone, welding time and welding pressure) on the breaking strength of ultrasonic welds. Among them, the influence level of welding time t is 45.31 %, the weld shape is Pattern 2 with the rate of 30.03 %, and the welding pressure is 24.66 %. Carrying out a verification test with the welding parameters: t=1.6 s, p=3.1 kgf/cm2, two patterns ( Pattern 2 and Pattern 3), the result of breaking strength for patterns was achieved. Pattern 2 has a difference of 1.19 % between the regression equation results and the actual experimental results, while the figure for Pattern 3 is 0.77 %. From these results, it is possible to select the appropriate technological parameters for ultrasonic welding equipment when processing products from nonwoven fabrics to ensure the highest quality and productivit

Continuing Professional Development for RMIT International University Vietnam Library Staff: Adding Value through an International Partnership / Julia Leong and Loc Huu Nguyen

The aim of this study was to explore the effectiveness of blended learning – the fusion of face-to-face and online learning experiences – to implement an effective and culturally sensitive program of professional development in an Australian university working in a developing country. It sought insight into pertinent pedagogical approaches for staff development across multiple locations including across national boundaries. The project demonstrates how learners can develop new capabilities and approaches by building on existing skills and knowledge as they interact in communities of practice. The immediate purpose was to design and deliver a continuing professional education program to meet the needs of librarians working at RMIT International University Vietnam in the context of the demands of the academic community and in the light of the challenge library staff experienced in seeking to meet explicit and tacit expectations. The project ran from late January to mid December 2010. The research questions were: „Is blended learning effective as an approach to continuing professional development when working across cultures in a multinational organization?‘ and ‗What contribution do face-to-face and online components make to learning outcomes?‘ The methodology used was an action learning approach. A 2009 consultant's report into the RMIT Vietnam Library established professional developmental needs which were further detailed in February 2010 by the project leader from RMIT University, Melbourne using a skills audit. Workshops in Vietnam, visits to Melbourne by several Vietnam staff members, and an online forum were then delivered. Reflective practice and ongoing input from staff was utilized to form a feedback loop to modify the project timing and approaches as needed. Evaluation included participant feedback on workshops, tracking changes in Library services, a customer survey, a project-end survey of participants' behavioral changes against learning topics as self-reported, and discussion with participants. The authors were actively involved in the project: Julia Leong as project leader and Loc Nguyen as project champion at the Saigon South Campus. Blended learning was found to be effective in meeting continuing professional developmental needs and in promoting positive changes in library service provision. Online discussions were effective for extending existing knowledge, gaining practical hints, and examining attitudes. Face-to-face workshops and visits were more effective for learning new material in a systematic way. It is recommended that consideration be given to applying the blended learning model used in this project to continuing professional developmental work in similar contexts

Continuing professional development for RMIT International University Vietnam Library staff : adding value through an international partnership / Julia Leong and Loc Huu Nguyen

The aim of this study was to explore the effectiveness of blended learning - the fusion of face-to-face and online learning experiences - to implement an effective and culturally sensitive program of professional development in an Australian university working in a developing country. It sought insight into pertinent pedagogical approaches for staff development across multiple locations including across national boundaries. The project demonstrates how learners can develop new capabilities and approaches by building on existing skills and knowledge as they interact in communities of practice. The immediate purpose was to design and deliver a continuing professional education program to meet the needs of librarians working at RMIT International University Vietnam in the context of the demands of the academic community and in the light of the challenge library staff experienced in seeking to meet explicit and tacit expectations. The project ran from late January to mid December 2010. The research questions were: Js blended learning effective as an approach to continuing professional development when working across cultures in a multinational organization?' and What contribution do face-to-face and online components make to learning outcomes?' The methodology used was an action learning approach, A 2009 consultant's report into the RMIT Vietnam Library established professional developmental needs which were further detailed in February 2010 by the project leader from RMIT University, Melbourne using a skills audit. Workshops in Vietnam, visits to Melbourne by several Vietnam staff members, and an online forum were then delivered. Reflective practice and ongoing input from staff was utilized to form a feedback loop to modify the project timing and approaches as needed. Evaluation included participant feedback on workshops, tracking changes in Library services, a customer survey, a project-end survey of participants' behavioral changes against learning topics as self-reported, and discussion with participants. The authors were actively involved in the project: Julia Leong as project leader and Loc Nguyen as project champion at the Saigon South Campus. Blended learning was found to be effective in meeting continuing professional developmental needs and in promoting positive changes in library service provision. Online discussions were effective for extending existing knowledge, gaining practical hints, and examining attitudes. Face-toface workshops and visits were more effective for learning new material in a systematic way. It is recommended that consideration be given to applying the blended learning model used in this project to continuing professional developmental work in similar contexts

The Effectiveness of Applying Realistic Mathematics Education Approach in Teaching Statistics in Grade 7 to Students' Mathematical Skills

The research was carried out to verify the effectiveness of applying Realistic Mathematics Education (RME) on the development of skills required by students in statistical content in grade 7. For achieving research objectives, the pedagogical experiment was conducted in the form of intrinsic legalization for forty-eight 7th-grade students at Tang Phu Nhan B Junior School, District 9, Ho Chi Minh City, Vietnam. Accordingly, data on pre-test results, study sheets, post-test, and student learning performance were collected and analyzed qualitatively. The results were assessed based on the criteria corresponding to the required skills for the statistical content, including the criteria for data collection, classification, and representation according to the given criteria for the skill, data collection, and organization capabilities; simple problem formation and problem-solving criteria arise from the existing statistical figures and charts for data analysis and processing skills. The primary mathematical statistics method was used to evaluate the achievement level of students for each criterion. Thereby, the experimental results showed that applying the RME approach in teaching statistical content positively impacted the development of some skills that students needed to achieve. Also, a number of guidelines were provided to guide the enhancement of RME activities

A Fuzzy LQR PID Control for a Two-Legged Wheel Robot with Uncertainties and Variant Height

This paper proposes a fuzzy LQR PID control for a two-legged wheeled balancing robot for keeping stability against uncertainties and variant heights. The proposed control includes the fuzzy supervisor, LQR, PID, and two calibrations. The fuzzy LQR is conducted to control the stability and motion of the robot while its posture changes with respect to time. The fuzzy supervisor is used to adjust the LQR control according to the robotic height. It consists of one input and one output. The input and output have three membership functions, respectively, to three postures of the robot. The PID control is used to control the posture of the robot. The first calibration is used to compensate for the bias value of the tilting angle when the robot changes its posture. The second calibration is applied to compute the robotic height according to the hip angle. In order to verify the effectiveness of the proposed control, a practical robot with the variant height is constructed, and the proposed control is embedded in the control board. Finally, two experiments are also conducted to verify the balancing and moving ability of the robot with the variant posture

An Effective PSO-inspired Algorithm for Workflow Scheduling

The Cloud is a computing platform that provides on-demand access to a shared pool of configurable resources such as networks, servers and storage that can be rapidly provisioned and released with minimal management effort from clients. At its core, Cloud computing focuses on maximizing the effectiveness of the shared resources. Therefore, workflow scheduling is one of the challenges that the Cloud must tackle especially if a large number of tasks are executed on geographically distributed servers. This entails the need to adopt an effective scheduling algorithm in order to minimize task completion time (makespan). Although workflow scheduling has been the focus of many researchers, a handful efficient solutions have been proposed for Cloud computing. In this paper, we propose the LPSO, a novel algorithm for workflow scheduling problem that is based on the Particle Swarm Optimization method. Our proposed algorithm not only ensures a fast convergence but also prevents getting trapped in local extrema. We ran realistic scenarios using CloudSim and found that LPSO is superior to previously proposed algorithms and noticed that the deviation between the solution found by LPSO and the optimal solution is negligible

FACTORS AFFECTING THE ACADEMIC RESULTS OF MASTER STUDENTS IN MATHEMATICS EDUCATION AT CAN THO UNIVERSITY, VIETNAM: A SURVEY STUDY

The study results were based on the survey data of 24 students  studying the master program in math education at Can Tho University, Vietnam. We used the questionnaire to find out the factors affecting students' learning outcomes: Learning time, learning conditions, learning environment, personal level, learning methods, collaborative learning, learning attitudes. The results show factors such as learning conditions, learning environment, time for leaning, qualifications, teaching methods, learning methods, cooperation in learning, attitude in learning are factors that significantly affect the learning of master students in Mathematics education. Therefore, universities with high-level training programs should have adequate facilities for students' learning; lecturers know how to use teaching methods to promote self-study and self-study for students, improve their ability to work independently, the ability to cooperate in the learning and research process of students. In other words, universities must uphold  their responsibilities when implementing intensive training programs, helping learners with necessary competencies as expected of the community and society.  Article visualizations

Effects of yeast extract and methyl jasmonate on the enhancement of solasodine biosynthesis in cell cultures of Solanum hainanense Hance

In this work, the effects of the elicitors methyl jasmonate (MeJA) and yeast extract (YE) on the growth and solasodine production of Solanum hainanense cells were investigated. The results showed that various concentrations of MeJA (50-250 µM) and YE (1-4 g/L) have different eliciting influences. The increase of solasodine content induced by the elicitation of 3 g/L of YE and 50 µM of MeJA at the beginning of cell culture was about 1.9- and 1.3-fold, respectively, as compared with that of the non-elicitated cells. In general, YE (biotic elicitor) was more effective in enhancing solasodine production than MeJA (abiotic elicitor)