Aiming at the problem of relative navigation for non-cooperative rendezvous of spacecraft,this paper proposes a new angles-only navigation architecture using non-linear dynamics method. This method does not solve the ...Aiming at the problem of relative navigation for non-cooperative rendezvous of spacecraft,this paper proposes a new angles-only navigation architecture using non-linear dynamics method. This method does not solve the problem of poor observability of angles-only navigation through orbital or attitude maneuvering,but improves the observability of angles-only navigation through capturing the non-linearity of the system in the evolution of relative motion. First,three relative dynamics models and their corresponding line-of-sight(LoS)measurement equations are introduced,including the rectilinear state relative dynamics model,the curvilinear state relative dynamics model,and the relative orbital elements(ROE)state relative dynamics model. Then,an observability analysis theory based on the Gramian matrix is introduced to determine which relative dynamics model could maximize the observability of angles-only navigation. Next,an adaptive extended Kalman filtering scheme is proposed to solve the problem that the angles-only navigation filter using the non-linear dynamics method is sensitive to measurement noises. Finally,the performances of the proposed angles-only navigation architecture are tested by means of numerical simulations,which demonstrates that the angles-only navigation filtering scheme without orbital or attitude maneuvering is completely feasible through improving the modeling of the relative dynamics and LoS measurement equations.展开更多
There is no global definition of what constitutes a large class. The literature, for example, shows large classes as ranging between 25-30 learners in the United Kingdom, more than 35 learners in the US, and 60 or mor...There is no global definition of what constitutes a large class. The literature, for example, shows large classes as ranging between 25-30 learners in the United Kingdom, more than 35 learners in the US, and 60 or more learners in developing countries. The current study attempted to establish what instructional strategies could be introduced for improvement of teaching learning in the prevailing large classes. A review of research on teaching of large classes highlighted challenges that both teachers and students experience. Effective teaching and learning throughout the study was conceptualized as that situated within a social constructivist framework. This is a descriptive study in design. The literature component of the study utilized a content analysis methodology with a view to identifying strategies of practical application and potential to facilitate learning in large classes, such as Active Learning, Collaborativb Learning, Cooperative Learning, Inductive Teaching Methods, and novel practices including issues on environment for change are suggested. The empirical data indicated that teachers had devised strategies to cope with the large classes, but these needed further development. The implication for these findings is the need for teacher professional development through reflective practice.展开更多
This paper aims to discuss differences between human resource management （HRM） and strategic human resource management （SHRM）, and aims to discuss convergence or divergence between American and European HRM. There...This paper aims to discuss differences between human resource management （HRM） and strategic human resource management （SHRM）, and aims to discuss convergence or divergence between American and European HRM. Therefore, research question is what the similarities and differences are between European and American HRM. Research methodology is based on critical review of HRM literature. Therefore, this study aims to increase conceptual ability of human resource （HR） professionals. Major result is that HRM is related with employee performance, and SHRM is related with firm performance. Secondly, European HRM is becoming similar to American HRM. The difference between European and American HRM is social context and social partners. European HRM considers social partners in management of HR.展开更多
Comparative space-time thinking lies at the heart of spatiotemporally integrated social sciences. The multiple dimensions and scales of socioeconomic dynamics pose numerous challenges for the application and evaluatio...Comparative space-time thinking lies at the heart of spatiotemporally integrated social sciences. The multiple dimensions and scales of socioeconomic dynamics pose numerous challenges for the application and evaluation of public policies in the comparative context. At the same time, social scientists have been slow to adopt and implement new spatiotemporally explicit methods of data analysis due to the lack of extensible software packages, which becomes a major impediment to the promotion of spatiotemporal thinking. The proposed framework will address this need by developing a set of research questions based on space-time-distributional features of socioeconomic datasets. The authors aim to develop, evaluate, and implement this framework in an open source toolkit to comprehensively quantify the changes and level of hidden variation of space-time datasets across scales and dimensions. Free access to the source code allows a broader community to incorporate additional advances in perspectives and methods, thus facilitating interdisciplinary collaboration. Being written in Python, it is entirely cross-platform, lowering transmission costs in research and education.展开更多
Empowerment in learning has been a topic of discussion for the last two decades. Empowered learners are not only believed to achieve greater content learning but are also thought to better demonstrate competencies suc...Empowerment in learning has been a topic of discussion for the last two decades. Empowered learners are not only believed to achieve greater content learning but are also thought to better demonstrate competencies such as communication, teamwork, and problem solving. These competencies are becoming increasingly important as the role of professional accountants evolves and diversifies. This paper examines first-year accounting students＇ perceptions of empowerment based on two different learning styles： cooperative learning and traditional classroom instruction. A quantitative research design was used to survey 279 first-year business degree students studying at institutions in Libya. The results indicated that students who attended cooperative learning classes were more empowered in terms of the impact they believed they could have on class discussions and the meaningfulness they attributed to the tasks being discussed. In addition, students taught by cooperative learning methods recorded significantly higher end of term exam results than those students who received traditional classroom instruction. In conclusion, this research indicates that the teaching method used in classroom instruction may impact an accounting student＇s levels of empowerment and subsequently their critical thinking, problem solving, writing skills, and technical accounting competencies.展开更多
Previously founded as CCPIT Machinery and Electronics Sub- council and CCOIC Machinery and Electronics Chamber of Corn- merce in June,1988,CCPIT Electronics Sub-Council and CCOIC Electronics Chamber of Commerce were
基金supported by the China Aerospace Science and Technology Corporation Eighth Research Institute Industry-University-Research Cooperation Fund(No.SAST 2020-019)。
文摘Aiming at the problem of relative navigation for non-cooperative rendezvous of spacecraft,this paper proposes a new angles-only navigation architecture using non-linear dynamics method. This method does not solve the problem of poor observability of angles-only navigation through orbital or attitude maneuvering,but improves the observability of angles-only navigation through capturing the non-linearity of the system in the evolution of relative motion. First,three relative dynamics models and their corresponding line-of-sight(LoS)measurement equations are introduced,including the rectilinear state relative dynamics model,the curvilinear state relative dynamics model,and the relative orbital elements(ROE)state relative dynamics model. Then,an observability analysis theory based on the Gramian matrix is introduced to determine which relative dynamics model could maximize the observability of angles-only navigation. Next,an adaptive extended Kalman filtering scheme is proposed to solve the problem that the angles-only navigation filter using the non-linear dynamics method is sensitive to measurement noises. Finally,the performances of the proposed angles-only navigation architecture are tested by means of numerical simulations,which demonstrates that the angles-only navigation filtering scheme without orbital or attitude maneuvering is completely feasible through improving the modeling of the relative dynamics and LoS measurement equations.
文摘There is no global definition of what constitutes a large class. The literature, for example, shows large classes as ranging between 25-30 learners in the United Kingdom, more than 35 learners in the US, and 60 or more learners in developing countries. The current study attempted to establish what instructional strategies could be introduced for improvement of teaching learning in the prevailing large classes. A review of research on teaching of large classes highlighted challenges that both teachers and students experience. Effective teaching and learning throughout the study was conceptualized as that situated within a social constructivist framework. This is a descriptive study in design. The literature component of the study utilized a content analysis methodology with a view to identifying strategies of practical application and potential to facilitate learning in large classes, such as Active Learning, Collaborativb Learning, Cooperative Learning, Inductive Teaching Methods, and novel practices including issues on environment for change are suggested. The empirical data indicated that teachers had devised strategies to cope with the large classes, but these needed further development. The implication for these findings is the need for teacher professional development through reflective practice.
文摘This paper aims to discuss differences between human resource management （HRM） and strategic human resource management （SHRM）, and aims to discuss convergence or divergence between American and European HRM. Therefore, research question is what the similarities and differences are between European and American HRM. Research methodology is based on critical review of HRM literature. Therefore, this study aims to increase conceptual ability of human resource （HR） professionals. Major result is that HRM is related with employee performance, and SHRM is related with firm performance. Secondly, European HRM is becoming similar to American HRM. The difference between European and American HRM is social context and social partners. European HRM considers social partners in management of HR.
基金Under the auspices of Humanities and Social Science Research,Major Project of Chinese Ministry of Education(No.13JJD790008)Basic Research Funds of National Higher Education Institutions of China(No.2722013JC030)+2 种基金Zhongnan University of Economics and Law 2012 Talent Grant(No.31541210702)Key Research Program of Chinese Academy of Sciences(No.KZZD-EW-06-03,KSZD-EW-Z-021-03)National Key Science and Technology Support Program of China(No.2012BAH35B03)
文摘Comparative space-time thinking lies at the heart of spatiotemporally integrated social sciences. The multiple dimensions and scales of socioeconomic dynamics pose numerous challenges for the application and evaluation of public policies in the comparative context. At the same time, social scientists have been slow to adopt and implement new spatiotemporally explicit methods of data analysis due to the lack of extensible software packages, which becomes a major impediment to the promotion of spatiotemporal thinking. The proposed framework will address this need by developing a set of research questions based on space-time-distributional features of socioeconomic datasets. The authors aim to develop, evaluate, and implement this framework in an open source toolkit to comprehensively quantify the changes and level of hidden variation of space-time datasets across scales and dimensions. Free access to the source code allows a broader community to incorporate additional advances in perspectives and methods, thus facilitating interdisciplinary collaboration. Being written in Python, it is entirely cross-platform, lowering transmission costs in research and education.
文摘Empowerment in learning has been a topic of discussion for the last two decades. Empowered learners are not only believed to achieve greater content learning but are also thought to better demonstrate competencies such as communication, teamwork, and problem solving. These competencies are becoming increasingly important as the role of professional accountants evolves and diversifies. This paper examines first-year accounting students＇ perceptions of empowerment based on two different learning styles： cooperative learning and traditional classroom instruction. A quantitative research design was used to survey 279 first-year business degree students studying at institutions in Libya. The results indicated that students who attended cooperative learning classes were more empowered in terms of the impact they believed they could have on class discussions and the meaningfulness they attributed to the tasks being discussed. In addition, students taught by cooperative learning methods recorded significantly higher end of term exam results than those students who received traditional classroom instruction. In conclusion, this research indicates that the teaching method used in classroom instruction may impact an accounting student＇s levels of empowerment and subsequently their critical thinking, problem solving, writing skills, and technical accounting competencies.
文摘Previously founded as CCPIT Machinery and Electronics Sub- council and CCOIC Machinery and Electronics Chamber of Corn- merce in June,1988,CCPIT Electronics Sub-Council and CCOIC Electronics Chamber of Commerce were
