Ethiopia is an agrarian country and agriculture is the backbone of its economy. Consequently, the government of Ethiopia has devised Agricultural Development Led Industrialization (ADLI) as the country’s overall econ...Ethiopia is an agrarian country and agriculture is the backbone of its economy. Consequently, the government of Ethiopia has devised Agricultural Development Led Industrialization (ADLI) as the country’s overall economic development policy. For the last 15 years, public investment towards the expansion of higher education, research and extension in agriculture has been so enormous. In reality, however, these higher education and research institutions were not sufficiently responsive to rural transformation. Thus, to evaluate the role of higher education and research institutions in stimulating rural transformation and to identify main training constraints accountable for their poor performances in institutional learning and rural transformation is of paramount importance. To this effect focus group discussions and key informant interviews were conducted. Stratified and purposive sampling technique was dominantly employed during the survey studies. The result of the study has shown that higher education and research institutions were less responsive to address the actual problems of small-scale farmers and they were limited by a number of constraints/challenges to address the actual problems of farmers. The major constraints were, to list some, limited involvement in research and extension works by the university staff, students limited practical attachments of the training programmes with farming communities, limited infrastructures and facilities and limited availability of contextualized learning resources. In addressing the aforesaid constraints/challenges, the university staff should proportionally allocate time in the research and extension activities on top of practical teaching supported by local research results and experience;involving students on practical attachments both in their academic and vacation time;giving emphasis on basic training preparation like fulfilling libraries, laboratories, demonstration fields and transportation facilities;and lastly to revise the existing curriculum in to the direction of solving the real problems of the Amhara region then the country Ethiopia.展开更多
In this paper, a model of topology optimization with linear buckling constraints is established based on an independent and continuous mapping method to minimize the plate/shell structure weight. A composite exponenti...In this paper, a model of topology optimization with linear buckling constraints is established based on an independent and continuous mapping method to minimize the plate/shell structure weight. A composite exponential function（CEF） is selected as filtering functions for element weight, the element stiffness matrix and the element geometric stiffness matrix, which recognize the design variables, and to implement the changing process of design variables from“discrete” to “continuous” and back to “discrete”. The buckling constraints are approximated as explicit formulations based on the Taylor expansion and the filtering function. The optimization model is transformed to dual programming and solved by the dual sequence quadratic programming algorithm. Finally, three numerical examples with power function and CEF as filter function are analyzed and discussed to demonstrate the feasibility and efficiency of the proposed method.展开更多
The Gauss-Markov （GM） model and the Errors-in-Variables （EIV） model are frequently used to perform 3D coordinate transformations in geodesy and engineering surveys. In these applications, because the observation e...The Gauss-Markov （GM） model and the Errors-in-Variables （EIV） model are frequently used to perform 3D coordinate transformations in geodesy and engineering surveys. In these applications, because the observation errors in original coordinates system are also taken into account, the latter is more accurate and reasonable than the former. Although the Weighted Total Least Squares （WTLS） technique has been intro- duced into coordinate transformations as the measured points are heteroscedastic and correlated, the Variance- Covariance Matrix （VCM） of observations is restricted by a particular structure, namely, only the correlations of each points are taken into account. Because the 3D datum transformation with large rotation angle is a non- linear problem, the WTLS is no longer suitable in this ease. In this contribution, we suggested the nonlinear WTLS adjustments with equality constraints （NWTLS-EC） for 3D datum transformation with large rotation an- gle, which removed the particular structure restriction on the VCM. The Least Squares adjustment with Equality （LSE） constraints is employed to solve NWTLS-EC as the nonlinear model has been linearized, and an iterative algorithm is proposed with the LSE solution. A simulation study of 3D datum transformation with large rotation angle is given to insight into the feasibility of our algorithm at last.展开更多
In this paper, we propose a modified evolutionary programming with dynamic domain for solving nonlinear IP/MIP problems with linear constraints, without involving penalty function or any transformation for the problem...In this paper, we propose a modified evolutionary programming with dynamic domain for solving nonlinear IP/MIP problems with linear constraints, without involving penalty function or any transformation for the problem to a linear model or others. The numerical results show that the new algorithm gives a satisfactory performance in which it works of high speed, and accuracy in IP/MIP problems.展开更多
A family of integrable systems of Liouville are obtained by, Tu pattern. Using higher-order potential-eigenfunction constraints, the integrable systems are factorized to two x- and t(n)-integrable Hamiltonian systems ...A family of integrable systems of Liouville are obtained by, Tu pattern. Using higher-order potential-eigenfunction constraints, the integrable systems are factorized to two x- and t(n)-integrable Hamiltonian systems whose Lax representation and three kinds of Darboux transformations are presented.展开更多
文摘Ethiopia is an agrarian country and agriculture is the backbone of its economy. Consequently, the government of Ethiopia has devised Agricultural Development Led Industrialization (ADLI) as the country’s overall economic development policy. For the last 15 years, public investment towards the expansion of higher education, research and extension in agriculture has been so enormous. In reality, however, these higher education and research institutions were not sufficiently responsive to rural transformation. Thus, to evaluate the role of higher education and research institutions in stimulating rural transformation and to identify main training constraints accountable for their poor performances in institutional learning and rural transformation is of paramount importance. To this effect focus group discussions and key informant interviews were conducted. Stratified and purposive sampling technique was dominantly employed during the survey studies. The result of the study has shown that higher education and research institutions were less responsive to address the actual problems of small-scale farmers and they were limited by a number of constraints/challenges to address the actual problems of farmers. The major constraints were, to list some, limited involvement in research and extension works by the university staff, students limited practical attachments of the training programmes with farming communities, limited infrastructures and facilities and limited availability of contextualized learning resources. In addressing the aforesaid constraints/challenges, the university staff should proportionally allocate time in the research and extension activities on top of practical teaching supported by local research results and experience;involving students on practical attachments both in their academic and vacation time;giving emphasis on basic training preparation like fulfilling libraries, laboratories, demonstration fields and transportation facilities;and lastly to revise the existing curriculum in to the direction of solving the real problems of the Amhara region then the country Ethiopia.
基金supported by the National Natural Science Foundation of China(Grants 11072009,111720131)
文摘In this paper, a model of topology optimization with linear buckling constraints is established based on an independent and continuous mapping method to minimize the plate/shell structure weight. A composite exponential function（CEF） is selected as filtering functions for element weight, the element stiffness matrix and the element geometric stiffness matrix, which recognize the design variables, and to implement the changing process of design variables from“discrete” to “continuous” and back to “discrete”. The buckling constraints are approximated as explicit formulations based on the Taylor expansion and the filtering function. The optimization model is transformed to dual programming and solved by the dual sequence quadratic programming algorithm. Finally, three numerical examples with power function and CEF as filter function are analyzed and discussed to demonstrate the feasibility and efficiency of the proposed method.
基金supported by the National Natural Science Foundation of China(41074017)
文摘The Gauss-Markov （GM） model and the Errors-in-Variables （EIV） model are frequently used to perform 3D coordinate transformations in geodesy and engineering surveys. In these applications, because the observation errors in original coordinates system are also taken into account, the latter is more accurate and reasonable than the former. Although the Weighted Total Least Squares （WTLS） technique has been intro- duced into coordinate transformations as the measured points are heteroscedastic and correlated, the Variance- Covariance Matrix （VCM） of observations is restricted by a particular structure, namely, only the correlations of each points are taken into account. Because the 3D datum transformation with large rotation angle is a non- linear problem, the WTLS is no longer suitable in this ease. In this contribution, we suggested the nonlinear WTLS adjustments with equality constraints （NWTLS-EC） for 3D datum transformation with large rotation an- gle, which removed the particular structure restriction on the VCM. The Least Squares adjustment with Equality （LSE） constraints is employed to solve NWTLS-EC as the nonlinear model has been linearized, and an iterative algorithm is proposed with the LSE solution. A simulation study of 3D datum transformation with large rotation angle is given to insight into the feasibility of our algorithm at last.
基金This project was supported by the National Natural Science Foundation of China.
文摘In this paper, we propose a modified evolutionary programming with dynamic domain for solving nonlinear IP/MIP problems with linear constraints, without involving penalty function or any transformation for the problem to a linear model or others. The numerical results show that the new algorithm gives a satisfactory performance in which it works of high speed, and accuracy in IP/MIP problems.
文摘A family of integrable systems of Liouville are obtained by, Tu pattern. Using higher-order potential-eigenfunction constraints, the integrable systems are factorized to two x- and t(n)-integrable Hamiltonian systems whose Lax representation and three kinds of Darboux transformations are presented.
