Recent geochemical and geophysical data from the Moon enable a revision of earlier interpretations regarding lunar origin, structure and bulk composition. Earth and Moon show many similarities among their isotopic com...Recent geochemical and geophysical data from the Moon enable a revision of earlier interpretations regarding lunar origin, structure and bulk composition. Earth and Moon show many similarities among their isotopic compositions, but they have evolved in totally dissimilar ways, probably related to the deficiency of water and volatile elements in the Moon as well as the vast differences in size and internal pressure. Some global geochemical differences from the Earth such as volatile depletion based on K/U ratios have been established. However, all current lunar samples come from differentiated regions, making the establishment of a bulk composition more reliant on bulk geophysical properties or isotopic similarities; it remains unclear how the latter arose or relate to whole Moon composition. The lack of fractionation effects among the refractory and super-refractory elements indicates that the proto-lunar material seems unlikely to have been vaporized while the presence of volatile elements may place lower limits on proto-lunar temperatures. The apparent lack of geochemical evidence of an impacting body enables other possible impactors, such as comets, to be considered. Although the origin of the Moon remains currently unknown, it is generally believed that the Moon originated as the result of a giant impact on the Earth.展开更多
Recently, global financial crisis or meltdown rocked the international financial market. This havoc was the result of the reckless use of financial derivatives that received spontaneous patronization from the financia...Recently, global financial crisis or meltdown rocked the international financial market. This havoc was the result of the reckless use of financial derivatives that received spontaneous patronization from the financial whiz, but it is strange to discover that those proponents of market economy embarked on policy that was purely Keynesian in principle. The episode started in August 2007 with the collapse of subprime mortgage market and reached its climax during August 2008. Central banks in many countries of the western world intervened in the market to pump additional fund to give buoyancy in the credit market. The crisis encapsulated with the queer idea of financial instruments and multiple origins related to subprime mortgage left its trail in both developed and developing countries. Thus, an elaborate analysis of the causal link among various innovative instruments highlighting a mismatch between academic doctrine and real-life perspective and the inadequacy of the institutional arrangements supposed to tame the volatility of the market may be a useful guide to financial analysts and policy planners. The purpose of this paper is to highlight systemic gaps in the meltdown and redefine the contour of macroeconomics most appropriate to weather such catastrophe in the future.展开更多
This paper studies relationships between the best linear unbiased estimators （BLUEs） of an estimable parametric functions Kβunder the Gauss-Markov model {y, Xβ, σ^2]E} and its misspecified model {y, X0β,σ^2∑0}...This paper studies relationships between the best linear unbiased estimators （BLUEs） of an estimable parametric functions Kβunder the Gauss-Markov model {y, Xβ, σ^2]E} and its misspecified model {y, X0β,σ^2∑0}. In addition, relationships between BLUEs under a restricted Gauss Markov model and its misspecified model are also investigated.展开更多
Purpose – In the process of robot shell design, it is necessary to match the shape of the input 3D originalcharacter mesh model and robot endoskeleton, in order to make the input model fit for robot and avoidcollisio...Purpose – In the process of robot shell design, it is necessary to match the shape of the input 3D originalcharacter mesh model and robot endoskeleton, in order to make the input model fit for robot and avoidcollision. So, the purpose of this paper is to find an object of reference, which can be used for the process ofshape matching.Design/methodology/approach – In this work, the authors propose an interior bounded box (IBB)approach that derives from oriented bounding box (OBB). This kind of box is inside the closed mesh model.At the same time, it has maximum volume which is aligned with the object axis but is enclosed by all the meshvertices. Based on the IBB of input mesh model and the OBB of robot endoskeleton, the authors can completethe process of shape matching. In this paper, the authors use an evolutionary algorithm, covariance matrixadaptation evolution strategy (CMA-ES), to approximate the IBB based on skeleton and symmetry of inputcharacter mesh model.Findings – Based on the evolutionary algorithm CMA-ES, the optimal position and scale informationof IBB can be found. The authors can obtain satisfactory IBB result after this optimization process.The output IBB has maximum volume and is enveloped by the input character mesh model as well.Originality/value – To the best knowledge of the authors, the IBB is first proposed and used in the field ofrobot shell design. Taking advantage of the IBB, people can quickly obtain a shell model that fit for robot.At the same time, it can avoid collision between shell model and the robot endoskeleton.展开更多
文摘Recent geochemical and geophysical data from the Moon enable a revision of earlier interpretations regarding lunar origin, structure and bulk composition. Earth and Moon show many similarities among their isotopic compositions, but they have evolved in totally dissimilar ways, probably related to the deficiency of water and volatile elements in the Moon as well as the vast differences in size and internal pressure. Some global geochemical differences from the Earth such as volatile depletion based on K/U ratios have been established. However, all current lunar samples come from differentiated regions, making the establishment of a bulk composition more reliant on bulk geophysical properties or isotopic similarities; it remains unclear how the latter arose or relate to whole Moon composition. The lack of fractionation effects among the refractory and super-refractory elements indicates that the proto-lunar material seems unlikely to have been vaporized while the presence of volatile elements may place lower limits on proto-lunar temperatures. The apparent lack of geochemical evidence of an impacting body enables other possible impactors, such as comets, to be considered. Although the origin of the Moon remains currently unknown, it is generally believed that the Moon originated as the result of a giant impact on the Earth.
文摘Recently, global financial crisis or meltdown rocked the international financial market. This havoc was the result of the reckless use of financial derivatives that received spontaneous patronization from the financial whiz, but it is strange to discover that those proponents of market economy embarked on policy that was purely Keynesian in principle. The episode started in August 2007 with the collapse of subprime mortgage market and reached its climax during August 2008. Central banks in many countries of the western world intervened in the market to pump additional fund to give buoyancy in the credit market. The crisis encapsulated with the queer idea of financial instruments and multiple origins related to subprime mortgage left its trail in both developed and developing countries. Thus, an elaborate analysis of the causal link among various innovative instruments highlighting a mismatch between academic doctrine and real-life perspective and the inadequacy of the institutional arrangements supposed to tame the volatility of the market may be a useful guide to financial analysts and policy planners. The purpose of this paper is to highlight systemic gaps in the meltdown and redefine the contour of macroeconomics most appropriate to weather such catastrophe in the future.
基金Supported in part by National Natural Science Foundation of China (Grant No.70871073)
文摘This paper studies relationships between the best linear unbiased estimators （BLUEs） of an estimable parametric functions Kβunder the Gauss-Markov model {y, Xβ, σ^2]E} and its misspecified model {y, X0β,σ^2∑0}. In addition, relationships between BLUEs under a restricted Gauss Markov model and its misspecified model are also investigated.
基金This research,which is carried out at BeingThere Centre,collaboration among IMI of Nanyang Technological University(NTU)Singapore,ETH Zurich and UNC Chapel Hill,is supported by the Singapore National Research Foundation(NRF)under its International Research Centre@Singapore Funding Initiative and administered by the Interactive Digital Media Programme Office(IDMPO).The author Shihui Guo is supported by Chinese Post-doctoral Science Foundation 2016M600506.
文摘Purpose – In the process of robot shell design, it is necessary to match the shape of the input 3D originalcharacter mesh model and robot endoskeleton, in order to make the input model fit for robot and avoidcollision. So, the purpose of this paper is to find an object of reference, which can be used for the process ofshape matching.Design/methodology/approach – In this work, the authors propose an interior bounded box (IBB)approach that derives from oriented bounding box (OBB). This kind of box is inside the closed mesh model.At the same time, it has maximum volume which is aligned with the object axis but is enclosed by all the meshvertices. Based on the IBB of input mesh model and the OBB of robot endoskeleton, the authors can completethe process of shape matching. In this paper, the authors use an evolutionary algorithm, covariance matrixadaptation evolution strategy (CMA-ES), to approximate the IBB based on skeleton and symmetry of inputcharacter mesh model.Findings – Based on the evolutionary algorithm CMA-ES, the optimal position and scale informationof IBB can be found. The authors can obtain satisfactory IBB result after this optimization process.The output IBB has maximum volume and is enveloped by the input character mesh model as well.Originality/value – To the best knowledge of the authors, the IBB is first proposed and used in the field ofrobot shell design. Taking advantage of the IBB, people can quickly obtain a shell model that fit for robot.At the same time, it can avoid collision between shell model and the robot endoskeleton.
