Water allocation policies for the Dong Nai River Basin in Vietnam: an integrated perspective

Recent water sector reforms, increased scarcity and vulnerability of existing water resources, combined with declining public funding available for large-scale infrastructure investment in the sector have led to an increased awareness by the Government of Vietnam for the need to analyze water resource allocation and use in an integrated fashion, at the basin scale, and from an economic efficiency perspective. This paper presents the development, application, and results from an integrated economic-hydrologic river basin model for the Dong Nai River Basin in southern Vietnam that attempts to address these issues. The model framework takes into account the sectoral structure of water users (agriculture, industry, hydropower, households, and the environment), the location of water-using regions, and the institutions for water allocation in the basin. Water benefit functions are developed for the major water uses subject to physical, system control, and policy constraints. Based on this modeling framework, policies that can affect water allocation and use at the basin level, including both basin-specific and general macroeconomic policies, are analyzed.River basin model, water allocation policy, integrated assessment, Vietnam, Dong Nai basin, Water resources Economic aspects,

Mining high utility itemsets in massive transactional datasets

Mining High Utility Itemsets from a transaction database is to find itemsets that have utility beyond an user-specified threshold. Existing High Utility Itemsets mining algorithms suffer from many problems when being applied to massive transactional datasets. One major problem is the high memory dependency: the gigantic data structure built is assumed to fit in the computer main memory. This paper proposes a new disk-based High Utility Itemsets mining algorithm, which achieves its efficiency by applying three new ideas. First, transactional data is converted into a new database layout called Transactional Array that prevents multiple scanning of the database during the mining phase. Second, for each frequent item, a relatively small independent tree is built for summarizing co-occurrences. Finally, a simple and non-recursive mining process reduces the memory requirements as minimum candidacy generation and counting is needed. We have tested our algorithm on several very large transactional databases and the results show that our algorithm works efficiently

Factors associated with job satisfaction among district hospital health workers in Northern Vietnam : a cross-sectional study

Background: In many developing countries, including Vietnam, little is known about job satisfaction among lower level-health staff. The purpose of this study was to assess job satisfaction and its determinants among district hospital health staff. Methods: In a cross-sectional quantitative study, 128 health staff from a rural district hospital in Northern Vietnam were approached for data collection. Regression techniques were adopted to assess factors associated with several types of job satisfaction. Results: Overall job satisfaction was moderately high, ranging from 69% to 91%. Across all dimensions, health workers showed their highest satisfaction with co-worker relationships, while, in comparison, it was much lower for their supervisor's style and relationship. However, they claimed their lowest satisfaction with compensation and benefits. In final multivariate models, females and those satisfied with knowledge, skills and job performance were most likely to be satisfied with relationships with co-workers. Staff who were married, received a low pay, who were not satisfied with supervisor style and relationships and who were not satisfied with staff training, development opportunities were least likely to be satisfied with compensation and benefits. Conclusions: The study findings highlight an important need for designing an intervention program that considers organizational factors. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd

Universal Framework for Linear Motors and Multi-Axis Stages with Magnetic Levitation

This dissertation presents the electromagnetic design and experimental validation of a new framework for linear permanent-magnet (PM) machines with targeted applications in precision motion control. In this framework, a single forcer, which can generate two independent force components in two perpendicular directions, consists of a stationary Halbach magnet array and two Lorentz coils with a phase difference of 90° or 270°. Any number of coil pairs can be attached on the same moving frame to work with a common magnet array or matrix, forming a linear or planar PM motor. Key advantages of this framework are simple force calculation, a linear system model, and a reduced number of coils for force generation and allocation in multi-axis positioners. The proposed framework effectively allows for decoupled dynamics, simplifying the linear controller design and real-time implementation. To experimentally verify the theoretical framework proposed herein, a high-precision 6-axis magnetically levitated (maglev) stage is designed, constructed, and controlled. The development of this 6-axis positioning system is an integrated work, including magnetic-force calculation and analysis, mechanical design, fabrication, assembly, system modeling, system identification, and control system design. The mechanical components of the system include a stationary superimposed Halbach magnet matrix, which was previously built, and a moving platen with a plastic frame, four sets of 2-phase coils, and two precision mirrors. For position measurements, there are three laser interferometers for in-plane position measurements, three laser displacement sensors for out-of-plane position sensing, and two 2-channel Hall-effect sensors for the position feedback to initialize the position and expand the travel ranges of the platen in the XY plane. The positioning resolutions of 10 nm in the xy plane and in the vertical axis are demonstrated. In out-of-plane rotation about the two horizontal axes, experimental results show the unprecedented positioning resolution of 0.1 μrad. The maximum travel range in X and Y with nanoscale positioning resolution is 56 mm × 35 mm, limited by the lengths of the precision mirrors attached to the platen. With the trapezoidal-velocity input shaping, achieved performance specifications include the maximum acceleration and velocity of 0.6 m/s2 and 0.06 m/s, respectively, in translations in the horizontal plane. With the platen supported by the air bearings, the maximum acceleration and speed are 1.5 m/s2 and 0.15 m/s, respectively. A load test is performed with the platen carrying a load of 0.54 kg, which is 72% of its total mass, magnetically levitated in 6- axis closed-loop control. Experimental results show the reduced coupled dynamics between different axes in magnetic levitation. This framework of 2-phase Lorentz coils and linear Halbach arrays is highly applicable in precision-positioning linear motors and multi-axis stages, steppers, scanners, nano-scale manipulation and alignment systems, and vibration isolators

BLENDED LEARNING IN BADMINTON TRAINING FOR PROFESSIONALS: STUDENTS’ PERCEPTIONS AND PERFORMANCE IMPACTS

As with other subject areas, badminton instruction for practitioners is experiencing a lot of changes under the impact of technology. Recently there has been the possibility of moving badminton training classes to the online platform but there is no consensus on its efficacy. This study is conducted to study the effects of blended learning activities on the perceptions and performance of students in physical education. Forty students in physical education are selected and divided into two groups: an experimental group, and a control group. All groups in face-to-face learning sessions have the same curriculum, course-book, equipment and teaching method. The questionnaire and interview data show that students in blended class sessions had positive perceptions of learning activities.  Article visualizations

A Design Framework and AI System for Affective Destination Image Generation to Influence Tourists’ Emotional Response

Affective destination images have received considerable attention from tourism marketing researchers as evidence suggests that affective components in destination images affect tourists’ emotional responses, which in turn influence their behavioural intentions toward the destination. Therefore, tourism practitioners seek solutions to influence the emotional effects of affective destination images for B2C communication. This paper presents a design science research project to develop an AI system to assist practitioners in generating affective destination images that potentially trigger the desired emotional responses of tourists. By leveraging knowledge and techniques from NeuroIS, this paper also proposes a framework of scientific experiments to assess how the generated affective destination images by the AI system affect tourists’ emotional experiences

A Multi-axis Compact Positioner with a 6-coil Platen Moving Over a Superimposed Halbach Magnet Matrix

A multi-axis compact positioner is designed and implemented in this thesis. The single-moving-part positioner is designed to move in the magnetic field generated by a superimposed concentrated-field permanent magnet matrix. The compact positioner is primarily for the stepping and scanning applications that require 3-DOF planar motions. In which, the travel ranges in two orthogonal directions are on the order of 100 mm. The moving platen, which has the size of 185.4 mm x 157.9 mm and weighs 0.64 kg, mainly comprises of a plastic frame and six copper coils. It is actuated in the horizontal plane by flowing six independent electric currents into the coils. The platen is supported against gravity by three air bearings. Force calculation is based on the Lorentz force law. With a current-carrying rectangular coil placed in the magnetic field of the supper-imposed Hallbach magnet matrix, the force acting on the coil is calculated by volume integration. The distances between the longer sides and between the shorter sides of the rectangular coil are designed to fit a half pitch and one pitch of the Hallbach magnet array, respectively. Therefore, the volume integration is simplified considerably. The force-current relation for the entire platen with six coils is derived. Three Hall-effect sensors are attached to the moving platen to measure the magnetic flux densities at the center points of the sensors. The position of the moving platen is determined by the field solution of the magnet matrix and the magnetic flux densities sensed by the Hall-effect sensors. A new discrete PID-like controller is proposed and tested. For the step responses with the step sizes within 1000 micrometers, the overshoots and the steady state errors are negligible. The achieved velocity in x is 10.50 cm/s and in y is 16.25 cm/s, respectively. The achieved acceleration in x is 43.75 cm/s^2 and in y is 95.59 cm/s^2, respectively. The achieved travel ranges are 15.24 cm in x, 20.32 cm in y, and 0.21 rad in the rotational motions about the vertical axis. The positioning resolution in x and y is 8 micrometers with the rms positioning error of 6 micrometers. The positioning resolution in rotation about the vertical axis is 130 microrad

Trends in, projections of, and inequalities in reproductive, maternal, newborn and child health service coverage in Vietnam 2000-2030 : a Bayesian analysis at national and sub-national levels

Background: To assess the reproductive, maternal, newborn and child health (RMNCH) service coverage in Vietnam with trends in 2000−2014, projections and probability of achieving targets in 2030 at national and sub-national levels; and to analyze the socioeconomic, regional and urban-rural inequalities in RMNCH service indicators. Methods: We used national population-based datasets of 44,624 households in Vietnam from 2000 to 2014. We applied Bayesian regression models to estimate the trends in and projections of RMNCH indicators and the probabilities of achieving the 2030 targets. Using the relative index, slope index, and concentration index of inequality, we examined the patterns and trends in RMNCH coverage inequality. Findings: We projected that 9 out of 17 health service indicators (53%) would likely achieve the 2030 targets at the national level, including at least one and four ANC visits, BCG immunization, access to improved water and adequate sanitation, institutional delivery, skilled birth attendance, care-seeking for pneumonia, and ARI treatment. We observed very low coverages and zero chance of achieving the 2030 targets at national and sub-national levels in early initiation and exclusive breastfeeding, family planning needs satisfied, and oral rehydration therapy. The most deprived households living in rural areas and the Northwest, Northeast, North Central, Central Highlands, and Mekong River Delta regions would not reach the 80% immunization coverage of DPT3, Polio3, Measles and full immunization. We found socioeconomic, regional, and urban-rural inequalities in all RMNCH indicators in 2014 and no change in inequalities over 15 years in the lowest-coverage indicators. Interpretation: Vietnam has made substantial progress toward UHC. By improving the government's health system reform efforts, re-allocating resources focusing on people in the most impoverished rural regions, and restructuring and enhancing current health programs, Vietnam can achieve the UHC targets and other health-related SDGs. Funding: The authors did not receive any funds for conducting this study. © 2021 The Author(s

Estimation of Above-Ground Mangrove Biomass Using Landsat-8 Data- Derived Vegetation Indices: A Case Study in Quang Ninh Province, Vietnam

This study aimed to map the status of mangrove forests over the coasts of Hai Ha District and Mong Cai City in Quang Ninh Province by using 2019 Landsat-8 imagery. It then developed the AGB estimation model of mangrove forests based on the AGB estimation-derived plots inventory and vegetation indices-derived from Landsat-8 data. As results, there were five land covers identified, including mangrove forests, other vegetation, wetlands, built-up, and water, with the overall accuracy assessments of 80.0% and Kappa coefficient of 0.74. The total extent of mangrove forests was estimated at 4291.2 ha. The best AGB estimation model that was selected to estimate the AGB and AGC of mangrove forests for the whole coasts of Hai Ha District and Mong Cai City is AGB= 30.38 + 911.95*SAVI (R2=0.924, PValue <0.001). The model validation assessment has confirmed that the selected AGB model can be applied to Hai Ha and Mong Cai coasts with the mean difference between AGB observed and AGB predicted at 16.0 %. This satisfactory AGB model also suggests a good potential for AGB and AGC mapping, which offer the carbon trading market in the study site. As the AGB model selected, the total AGB and AGC of mangrove forests were estimated at about 14,600,000 tons and 6,868,076 tons with a range of from 94.0 - 432.0 tons ha-1, from 44.2 - 203.02 tons ha-1, respectively. It also suggests that the newly-developed AGB model of mangrove forests can be used to estimate AGC stocks and carbon sequestration of mangrove forests for C-PFES in over the coasts of Hai Ha District and Mong Cai City, which is a very importantly financial source for mangrove forest managers, in particular for local mangrove protectors

On asymptotic periodic solutions of fractional differential equations and applications

In this paper we study the asymptotic behavior of solutions of fractional differential equations of the form $D^{\alpha}_Cu(t)=Au(t)+f(t), u(0)=x, 0<\alpha\le1, ( *)$ where $D^{\alpha}_Cu(t)$ is the derivative of the function $u$ in the Caputo's sense, $A$ is a linear operator in a Banach space \X that may be unbounded and $f$ satisfies the property that $\lim_{t\to \infty} (f(t+1)-f(t))=0$ which we will call asymptotic $1$-periodicity. By using the spectral theory of functions on the half line we derive analogs of Katznelson-Tzafriri and Massera Theorems. Namely, we give sufficient conditions in terms of spectral properties of the operator $A$ for all asymptotic mild solutions of Eq. (*) to be asymptotic $1$-periodic, or there exists an asymptotic mild solution that is asymptotic $1$-periodic.Comment: 13 pages. arXiv admin note: text overlap with arXiv:1910.0860