In this paper, a 2D transient finite element analysis was carried out for a new type of solar powered injera baking system. In the proposed system （currently under development）, heat transfer oil is heated using sol...In this paper, a 2D transient finite element analysis was carried out for a new type of solar powered injera baking system. In the proposed system （currently under development）, heat transfer oil is heated using solar energy by parabolic trough and the oil circulates through the space below the baking pan in the kitchen. Based on previous finite element study on existing electric injera baking pans, a new type of baking pan made from ceramic with 8 mm thickness was manufactured and used for the proposed system. The model was further extended to study the heat up time and temperature distributions during initial heat up and cyclic baking of the new model. The proposed baking pan that uses solar energy gives acceptable heat up and baking time compared to existing conventional baking methods. Generally, the finite element model predicts well the temperature distributions during initial heat up and cyclic baking.展开更多
The influences of vegetation on intraseasonal oscillation （ISO） were examined using the Community Atmosphere Model version 3 （CAM3）. Two 15-year numerical experiments were completed： the first was performed with ...The influences of vegetation on intraseasonal oscillation （ISO） were examined using the Community Atmosphere Model version 3 （CAM3）. Two 15-year numerical experiments were completed： the first was performed with a realistic vegetation distribution （VEG run）, and the second was identical to the VEG run except without land vegetation （NOVEG run）. Generally speak- ing, CAM3 was able to reproduce the spatial distribution of the ISO, but the ISO intensity in the simulation was much weaker than that observed in nature： the 1SO has a relatively much stronger signal. A comparison of the VEG run with the NOVEG run revealed that the presence of vegetation usually produces a weak ISO. The vegetation effects on ISO intensity were significant over West Africa and South Asia, especially in the summer half-year. Vegetation also plays an important role in modulating ISO propagation. The eastward propagation of the ISO in the VEG run was clearer than that in the NOVEG run over the West African and Maritime Continent regions. The northward propagation of the ISO in the VEG run was more consistent with observation than that in the NOVEG run.展开更多
Based on variable sized chunking, this paper proposes a content aware chunking scheme, called CAC, that does not assume fully random file contents, but tonsiders the characteristics of the file types. CAC uses a candi...Based on variable sized chunking, this paper proposes a content aware chunking scheme, called CAC, that does not assume fully random file contents, but tonsiders the characteristics of the file types. CAC uses a candidate anchor histogram and the file-type specific knowledge to refine how anchors are determined when performing de- duplication of file data and enforces the selected average chunk size. CAC yields more chunks being found which in turn produces smaller average chtmks and a better reduction in data. We present a detailed evaluation of CAC and the experimental results show that this scheme can improve the compression ratio chunking for file types whose bytes are not randomly distributed （from 11.3% to 16.7% according to different datasets）, and improve the write throughput on average by 9.7%.展开更多
A memory reduction technique is proposed for solving stationary kinetic model equations. As implied by an integral solution of the stationary kinetic equation, a velocity distribution function can be reconstructed fro...A memory reduction technique is proposed for solving stationary kinetic model equations. As implied by an integral solution of the stationary kinetic equation, a velocity distribution function can be reconstructed from given macroscopic variables. Based on this fact, we propose a technique to reconstruct distribution function at discrete level, and employ it to develop an implicit numerical method for kinetic equations. The new implicit method only stores the macroscopic quantities which appear in the collision term, and does not store the distribution functions. As a result, enormous memory requirement for solving kinetic equations is totally relieved. Several boundary conditions, such as, inlet, outlet and isothermal boundaries, are discussed. Some numerical tests demonstrate the validity and efficiency of the technique.The new implicit solver provides nearly identical solution as the explicit kinetic solver, while the memory requirement is on the same order as the Navier–Stokes solver.展开更多
文摘In this paper, a 2D transient finite element analysis was carried out for a new type of solar powered injera baking system. In the proposed system （currently under development）, heat transfer oil is heated using solar energy by parabolic trough and the oil circulates through the space below the baking pan in the kitchen. Based on previous finite element study on existing electric injera baking pans, a new type of baking pan made from ceramic with 8 mm thickness was manufactured and used for the proposed system. The model was further extended to study the heat up time and temperature distributions during initial heat up and cyclic baking of the new model. The proposed baking pan that uses solar energy gives acceptable heat up and baking time compared to existing conventional baking methods. Generally, the finite element model predicts well the temperature distributions during initial heat up and cyclic baking.
基金supported by the National Natural Science Foundation of China (General Program (Grant No.40905042)and Key Program (Grant No. 40830956))
文摘The influences of vegetation on intraseasonal oscillation （ISO） were examined using the Community Atmosphere Model version 3 （CAM3）. Two 15-year numerical experiments were completed： the first was performed with a realistic vegetation distribution （VEG run）, and the second was identical to the VEG run except without land vegetation （NOVEG run）. Generally speak- ing, CAM3 was able to reproduce the spatial distribution of the ISO, but the ISO intensity in the simulation was much weaker than that observed in nature： the 1SO has a relatively much stronger signal. A comparison of the VEG run with the NOVEG run revealed that the presence of vegetation usually produces a weak ISO. The vegetation effects on ISO intensity were significant over West Africa and South Asia, especially in the summer half-year. Vegetation also plays an important role in modulating ISO propagation. The eastward propagation of the ISO in the VEG run was clearer than that in the NOVEG run over the West African and Maritime Continent regions. The northward propagation of the ISO in the VEG run was more consistent with observation than that in the NOVEG run.
基金Supported by the National Natural Science Foundation of China （No.60673001） the State Key Development Program of Basic Research of China （No. 2004CB318203）.
文摘Based on variable sized chunking, this paper proposes a content aware chunking scheme, called CAC, that does not assume fully random file contents, but tonsiders the characteristics of the file types. CAC uses a candidate anchor histogram and the file-type specific knowledge to refine how anchors are determined when performing de- duplication of file data and enforces the selected average chunk size. CAC yields more chunks being found which in turn produces smaller average chtmks and a better reduction in data. We present a detailed evaluation of CAC and the experimental results show that this scheme can improve the compression ratio chunking for file types whose bytes are not randomly distributed （from 11.3% to 16.7% according to different datasets）, and improve the write throughput on average by 9.7%.
基金supported by the National Natural Science Foundation of China(11602091 and 91530319)the National Key Research and Development Plan(2016YFB0600805)
文摘A memory reduction technique is proposed for solving stationary kinetic model equations. As implied by an integral solution of the stationary kinetic equation, a velocity distribution function can be reconstructed from given macroscopic variables. Based on this fact, we propose a technique to reconstruct distribution function at discrete level, and employ it to develop an implicit numerical method for kinetic equations. The new implicit method only stores the macroscopic quantities which appear in the collision term, and does not store the distribution functions. As a result, enormous memory requirement for solving kinetic equations is totally relieved. Several boundary conditions, such as, inlet, outlet and isothermal boundaries, are discussed. Some numerical tests demonstrate the validity and efficiency of the technique.The new implicit solver provides nearly identical solution as the explicit kinetic solver, while the memory requirement is on the same order as the Navier–Stokes solver.
