A possible approach to assess the fine grain OSL dating is discussed through comparison of equivalent dose (DE) values and ages obtained by IRSL and GLSL of fine grains for 31 sediment samples from North China. The IR...A possible approach to assess the fine grain OSL dating is discussed through comparison of equivalent dose (DE) values and ages obtained by IRSL and GLSL of fine grains for 31 sediment samples from North China. The IRSL and GLSL were measured with the same aliquots for each sample, i.e. shine-down was by 100 s of IRSL (880 nm) followed by 100 s of GLSL (514 nm) on the same discs. The DE values and ages found by IRSL are in good agreement with those by GLSL within 1-2σ for 80% samples, especially for aeolian loess samples. Considering that IRSL from feldspar differs obviously from GLSL dominated from quartz in dose response, thermal stability and optical bleaching characteristic, the agreement between the DE values may be taken as evidence that the two clocks of IRSL and GLSL had been well reset during deposition. The consistent ages of IRSL and GLSL, in turn, may be referred to an indicator to evaluate the fine grain OSL dating of sediments.展开更多
The primary goal of cloth simulation is to express object behavior in a realistic manner and achieve real-time performance by following the fundamental concept of physic.In general,the mass–spring system is applied t...The primary goal of cloth simulation is to express object behavior in a realistic manner and achieve real-time performance by following the fundamental concept of physic.In general,the mass–spring system is applied to real-time cloth simulation with three types of springs.However,hard spring cloth simulation using the mass–spring system requires a small integration time-step in order to use a large stiffness coefficient.Furthermore,to obtain stable behavior,constraint enforcement is used instead of maintenance of the force of each spring.Constraint force computation involves a large sparse linear solving operation.Due to the large computation,we implement a cloth simulation using adaptive constraint activation and deactivation techniques that involve the mass-spring system and constraint enforcement method to prevent excessive elongation of cloth.At the same time,when the length of the spring is stretched or compressed over a defined threshold,adaptive constraint activation and deactivation method deactivates the spring and generate the implicit constraint.Traditional method that uses a serial process of the Central Processing Unit(CPU)to solve the system in every frame cannot handle the complex structure of cloth model in real-time.Our simulation utilizes the Graphic Processing Unit(GPU)parallel processing with compute shader in OpenGL Shading Language(GLSL)to solve the system effectively.In this paper,we design and implement parallel method for cloth simulation,and experiment on the performance and behavior comparison of the mass-spring system,constraint enforcement,and adaptive constraint activation and deactivation techniques the using GPU-based parallel method.展开更多
基金the National Natural Science Foundation of China (Grant No. 49872062) by the Chinese Academy of Sciences (Grant No. KZ951-A 1-402-07).
文摘A possible approach to assess the fine grain OSL dating is discussed through comparison of equivalent dose (DE) values and ages obtained by IRSL and GLSL of fine grains for 31 sediment samples from North China. The IRSL and GLSL were measured with the same aliquots for each sample, i.e. shine-down was by 100 s of IRSL (880 nm) followed by 100 s of GLSL (514 nm) on the same discs. The DE values and ages found by IRSL are in good agreement with those by GLSL within 1-2σ for 80% samples, especially for aeolian loess samples. Considering that IRSL from feldspar differs obviously from GLSL dominated from quartz in dose response, thermal stability and optical bleaching characteristic, the agreement between the DE values may be taken as evidence that the two clocks of IRSL and GLSL had been well reset during deposition. The consistent ages of IRSL and GLSL, in turn, may be referred to an indicator to evaluate the fine grain OSL dating of sediments.
文摘近年过,随着图形硬件及图形接口的更新换代,用于游戏的实时图形引擎得到了突飞猛进的发展,各种开源引擎与商业引擎层出不穷。该文旨在运用计算机图形学理论知识,基于OpenGL 3.3的标准以及GLSL着色语言,使用C＋＋语言编写和Visual Studio 2010平台,完成一个拥有模型载入、贴图载入、UI界面、地形系统以及人机交互系统的图形引擎,能够用于游戏场景与漫游类的应用。
基金supported by the Basic Science Research Program through the National Research Foundation of Korea(NRF-2019R1F1A1062752)funded by the Ministry of Education+1 种基金funded by BK21 FOUR(Fostering Outstanding Universities for Research)(No.:5199990914048)supported by the Soonchunhyang University Research Fund.
文摘The primary goal of cloth simulation is to express object behavior in a realistic manner and achieve real-time performance by following the fundamental concept of physic.In general,the mass–spring system is applied to real-time cloth simulation with three types of springs.However,hard spring cloth simulation using the mass–spring system requires a small integration time-step in order to use a large stiffness coefficient.Furthermore,to obtain stable behavior,constraint enforcement is used instead of maintenance of the force of each spring.Constraint force computation involves a large sparse linear solving operation.Due to the large computation,we implement a cloth simulation using adaptive constraint activation and deactivation techniques that involve the mass-spring system and constraint enforcement method to prevent excessive elongation of cloth.At the same time,when the length of the spring is stretched or compressed over a defined threshold,adaptive constraint activation and deactivation method deactivates the spring and generate the implicit constraint.Traditional method that uses a serial process of the Central Processing Unit(CPU)to solve the system in every frame cannot handle the complex structure of cloth model in real-time.Our simulation utilizes the Graphic Processing Unit(GPU)parallel processing with compute shader in OpenGL Shading Language(GLSL)to solve the system effectively.In this paper,we design and implement parallel method for cloth simulation,and experiment on the performance and behavior comparison of the mass-spring system,constraint enforcement,and adaptive constraint activation and deactivation techniques the using GPU-based parallel method.
