262 research outputs found

    Modified sunflower optimization for network reconfiguration and distributed generation placement

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    This paper proposed modified sunflower optimization (MSFO) for the combination of network reconfiguration and distributed generation placement problem (NR-DGP) to minimize power loss of the electric distribution system (EDS). Sunflower optimization (SFO) is inspired form the ideal of sunflower plant motion to get the sunlight and its reproduction. To enhance the performance of SFO, it is modified to MSFO wherein, the pollination and mortality techniques have been modified by using Levy distribution and mutation of the best solutions. The results are evaluated on two test systems. The efficiency of MSFO is compared with that of the original SFO and other algorithms in literature. The comparisons show that MSFO outperforms to SFO and other methods in obtained optimal solution. Furthermore, MSFO demonstrates the better statistical results than SFO. So, MSFO can be a powerful approach for the NR-DGP problem

    Assessment of High School Students’ Learning and Development of Qualities and Competencies: A Case Study

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    This study aims to assess high school students' learning outcomes, their achievement of goals and fulfilling academic requirements and how the entire teaching and learning process takes place. The study, consisting of an experimental group and a control group was conducted for pre-test and post-test comparisons of the academic performance of 88 10th grade students. 44 students were selected as the experimental group that underwent a specific teaching strategy to monitor their development of qualities and competencies in one semester, and the remaining 44 students acted as the control group. The data collected after the tests were analyzed using SPSS software (V20). The results showed that the students in the experimental group had better academic results than those in the control group. The findings of this study have implications for policy, further research as well as approaches for the assessment of students’ development of qualities and competencies in Vietnam

    Organisational Baseline Study: Overview report for Tra Hat CSV, Vietnam (VN03)

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    This report covers the Organisational Baseline Study (OBS) for the CCAFS Climate-Smart Village Tra Hat in the South Viet Nam. During October 2014 interviews were conducted with local stakeholders at ten organisations who are working or collaborating with farmers and/or the community in Vinh Loi district, Bac Lieu province. The Tra Hat CSV is located near the coastal area, at tail end of a primary canal of Quan Lo Phung Hiep system (QLPH), the Mekong Delta of Vietnam, it usually causes lack of fresh water in from QLPH in dry season. There are two distinct dry season (December to April) and rainy season (May to November) which typhoon happens seldom in rainy season. Protected by dyke and sluice system of QLPH in Bac Lieu province, Tra Hat has not been affected by saline intrusion for last 15 years. The main farming systems in the village comprise two or three rice crops per year, small livestock as pig, chicken and ducks. Besides, mixed fruit garden and cash crop are often blended in residential area. Ground water and water in ponds is popular in household to provide domestic water, raising fish or garden irrigation and livestock, especially in dry season. The objectives of the OBS study are to: Provide indicators to monitor changes in behaviours and practices of locally relevant organisations that have climate change related activities in Bac Lieu over time Understand the provision of information/services at the local level that informs farmers’ decision making about their livelihood strategies in response to climate change This OBS report also supplements to the quantitative Household Baseline Survey (HBS) and the qualitative Village Baseline Studies (VBS) in Tra Hat CSV and surrounding villages

    Asymptotic behavior of solutions of quasilinear differential-algebraic equations

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    This paper is concerned with the asymptotic behavior of solutions of linear differential-algebraic equations (DAEs) under small nonlinear perturbations. Some results on the asymptotic behavior of solutions which are well known for ordinary differential equations are extended to DAEs. The main tools are the projector-based decoupling and the contractive mapping principle. Under certain assumptions on the linear part and the nonlinear term, asymptotic behavior of solutions are characterized. As the main result, a Perron type theorem that establishes the exponential growth rate of solutions is formulated

    Village Baseline Study: Site Analysis Report for Tra Hat Village, Vinh Loi, Bac Lieu, Viet Nam (VNM 03)

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    This report presents data collected from the Village Baseline Study conducted on 2-4 October 2014 at the Tra Hat village, Vinh Loi district, Bac Lieu, Vietnam. Data were collected through focus group discussions and participatory resource mapping with community members in the village. The Village Baseline Study is part of the baseline activities conducted under the CGIAR Research Program on Climate Change, Agriculture, and Food Security (CCAFS) in South East Asia. The purpose is to collect data for indicators that will allow site comparability and monitoring to assess changes in terms of food security and natural resource management across time. Results show that the men and women in Tra Hat village consider farmland, rivers and canals as important natural resources. The quality, however, of land, water and wildlife habitats has declined in the last decade along with the improvement of farming techniques and intensive use of chemical fertilizers and pesticides. Infrastructures such as roads, internal canals, hospitals, schools, water supply station and electricity transformer station have improved. The future is envisioned to have improved internal canals in farmlands and a developed irrigation system, dykes and sluices to support high agriculture production. Home garden diversification was also believed to enhance food security and improve livelihood resilience. To turn the vision into reality, the community expects support from the different organizations working in the area considering current impacts of salinity intrusion and sea level rise, the need interventions of CCAFS and its partners. Strengthening the irrigation system, improving local rice variety, and introducing modern farming techniques taking into account negative impacts of climate change are major recommendation for future intervention

    Refinement of an inverse analysis procedure for estimating tensile constitutive law of UHPC

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    As regard to cementitious composite materials added a certain dosage of fiber, estimation of tensile constitutive law through inverse analysis methods is no longer extraordinary. However, development or improvement to achieve an effective method for estimating such a tensile behavior of fiber reinforced concrete (FRC) or Ultra high-performance concrete (UHPC) is still an interesting topic to researchers. In this respect, the paper presents a development of inverse analysis method developed by Lopez to obtain the stress-strain behavior of UHPC from the four-point bending test. By applying optimization algorithm into the iterative procedure of method, an improvement could be obtained for the inverse analysis with a high degree of automation in calculation. A post-process treatment for inverse analysis results is also proposed to bring a finer agreement between the tensile behavior curve obtained by the inverse analysis and result curve of uniaxial tensile test (UTT). The effectivity of process is shown through a comparison between the result obtained by the proposed method and the result in Lopez’s public paper

    Refinement of an inverse analysis procedure for estimating tensile constitutive law of UHPC

    Get PDF
    As regard to cementitious composite materials added a certain dosage of fiber, estimation of tensile constitutive law through inverse analysis methods is no longer extraordinary. However, development or improvement to achieve an effective method for estimating such a tensile behavior of fiber reinforced concrete (FRC) or Ultra high-performance concrete (UHPC) is still an interesting topic to researchers. In this respect, the paper presents a development of inverse analysis method developed by Lopez to obtain the stress-strain behavior of UHPC from the four-point bending test. By applying optimization algorithm into the iterative procedure of method, an improvement could be obtained for the inverse analysis with a high degree of automation in calculation. A post-process treatment for inverse analysis results is also proposed to bring a finer agreement between the tensile behavior curve obtained by the inverse analysis and result curve of uniaxial tensile test (UTT). The effectivity of process is shown through a comparison between the result obtained by the proposed method and the result in Lopez’s public paper

    Factors affecting farmers' decisions to participate in agricultural tourism activities: a case study in the Mekong Delta, Vietnam

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    Agricultural tourism, or agritourism, creates jobs for household members, diversifies farming activities and sources of revenue, and lowers the household's reliance on nature. This study uses Binary Logistic regression analysis to conduct a direct survey of 450 agricultural households in the Mekong Delta, Vietnam. The findings indicate that influencing factors include the following: support for local government policies; membership in farmer associations, unions, and extension clubs; awareness of the benefits of agritourism; a variety of production models; Internet access; education level; and membership in tourism associations, travel organisations. Distance between farms and agritourism destinations.Ho Phi Dinh (Phan Thiet University), Phuoc Huu Vo (Academy of Politics Region II), Duong Ngoc Pham (University of Finance and Marketing), Thanh Quang Ngo (School of Government, University of Economics)Includes bibliographical references

    Effects of Natural Disaster on Rice Production at Farm Level: New Evidence from Vietnam

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    The current study uses a unique balanced panel of 3,922 households between 2008 and 2010 to examine the extent to which rice production in Vietnam is affected by natural disasters and how coping strategies lessen the negative effects of natural disaster, using a fixed effects model that controls for time invariant farm heterogeneity. With regard to natural disaster, we find evidence of the negative inter-temporal occurrence and negative inter-temporal severity effects, and the negative current occurrence one as well. With regard to coping strategies, we find various evidence of current, inter-temporal coping-occurrence and coping severity effects, depending on kinds of coping strategies

    Effects of Natural Disaster on Rice Production at Farm Level: New Evidence from Vietnam

    Get PDF
    The current study uses a unique balanced panel of 3,922 households between 2008 and 2010 to examine the extent to which rice production in Vietnam is affected by natural disasters and how coping strategies lessen the negative effects of natural disaster, using a fixed effects model that controls for time invariant farm heterogeneity. With regard to natural disaster, we find evidence of the negative inter-temporal occurrence and negative inter-temporal severity effects, and the negative current occurrence one as well. With regard to coping strategies, we find various evidence of current, inter-temporal coping-occurrence and coping severity effects, depending on kinds of coping strategies
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