Land surface models are often highly nonlinear with model physics that contain parameterized discontinuities. These model attributes severely limit the application of advanced variational data assimilation methods int...Land surface models are often highly nonlinear with model physics that contain parameterized discontinuities. These model attributes severely limit the application of advanced variational data assimilation methods into land data assimilation. The ensemble Kalman filter (EnKF) has been widely employed for land data assimilation because of its simple conceptual formulation and relative ease of implementation. An updated ensemble-based three-dimensional variational assimilation (En3-DVar) method is proposed for land data assimilation.This new method incorporates Monte Carlo sampling strategies into the 3-D variational data assimilation framework. The proper orthogonal decomposition (POD) technique is used to efficiently approximate a forecast ensemble produced by the Monte Carlo method in a 3-D space that uses a set of base vectors that span the ensemble. The data assimilation process is thus significantly simplified. Our assimilation experiments indicate that this new En3-DVar method considerably outperforms the EnKF method by increasing assimilation precision. Furthermore, computational costs for the new En3-DVar method are much lower than for the EnKF method.展开更多
Abstract： The study aimed to assess the predictors of performance administered by the Philippine Regulation Commission （PRC） in the licensure examination of Maritime Academy of Asia and the Pacific （MAAP） for Aca...Abstract： The study aimed to assess the predictors of performance administered by the Philippine Regulation Commission （PRC） in the licensure examination of Maritime Academy of Asia and the Pacific （MAAP） for Academic Year 2007-2011. Specifically, this also aimed to answer the following questions： demographic profile of the maritime graduates, the college related factors, administrative related factors, the level of scholastic achievement of the graduates, and the performance of the graduates in the licensure examination. A total of one hundred seventy three （173） graduates of MAAP from Class 2007-2011 were utilized as the respondents for the study. The study found out that the results of pre board examination and scholastic achievement of the graduates had significant effect on the performance of the graduates in O.I.C Navigational Watch Licensure Examination. Other variables found out to have no significant effect on the result of the licensure examination of the graduates. Therefore, the null hypotheses that the demographic profile of the graduates, college related factors, and administrative related factors has no significant effect on scholastic the achievement of the students were accepted. However, the null hypothesis that scholastic achievement of the students has no significant effect on the performance in maritime licensure examination was rejected. The same way, the null hypothesis that the demographic profile of the graduates, college related factors and the administrative related factors has no significant effect on the performance in Officer in Charge--Navigational Watch licensure Examination were accepted.展开更多
基金supported by the National Natural Science Foundation of China (Grant No. 40705035)the National High Technology Research and Development Program of China (863 Program) (Grant Nos. 2009AA12Z129 and 2007AA12Z144)
文摘Land surface models are often highly nonlinear with model physics that contain parameterized discontinuities. These model attributes severely limit the application of advanced variational data assimilation methods into land data assimilation. The ensemble Kalman filter (EnKF) has been widely employed for land data assimilation because of its simple conceptual formulation and relative ease of implementation. An updated ensemble-based three-dimensional variational assimilation (En3-DVar) method is proposed for land data assimilation.This new method incorporates Monte Carlo sampling strategies into the 3-D variational data assimilation framework. The proper orthogonal decomposition (POD) technique is used to efficiently approximate a forecast ensemble produced by the Monte Carlo method in a 3-D space that uses a set of base vectors that span the ensemble. The data assimilation process is thus significantly simplified. Our assimilation experiments indicate that this new En3-DVar method considerably outperforms the EnKF method by increasing assimilation precision. Furthermore, computational costs for the new En3-DVar method are much lower than for the EnKF method.
文摘Abstract： The study aimed to assess the predictors of performance administered by the Philippine Regulation Commission （PRC） in the licensure examination of Maritime Academy of Asia and the Pacific （MAAP） for Academic Year 2007-2011. Specifically, this also aimed to answer the following questions： demographic profile of the maritime graduates, the college related factors, administrative related factors, the level of scholastic achievement of the graduates, and the performance of the graduates in the licensure examination. A total of one hundred seventy three （173） graduates of MAAP from Class 2007-2011 were utilized as the respondents for the study. The study found out that the results of pre board examination and scholastic achievement of the graduates had significant effect on the performance of the graduates in O.I.C Navigational Watch Licensure Examination. Other variables found out to have no significant effect on the result of the licensure examination of the graduates. Therefore, the null hypotheses that the demographic profile of the graduates, college related factors, and administrative related factors has no significant effect on scholastic the achievement of the students were accepted. However, the null hypothesis that scholastic achievement of the students has no significant effect on the performance in maritime licensure examination was rejected. The same way, the null hypothesis that the demographic profile of the graduates, college related factors and the administrative related factors has no significant effect on the performance in Officer in Charge--Navigational Watch licensure Examination were accepted.
