Equilibrium function in the cerebellum （vestibulo-cerebellar system） can deteriorate under the influence of alcohol. In the Romberg posture, the center of gravity, which was measured every 50 ms by stabilometry, app...Equilibrium function in the cerebellum （vestibulo-cerebellar system） can deteriorate under the influence of alcohol. In the Romberg posture, the center of gravity, which was measured every 50 ms by stabilometry, appeared to shift with alcohol ingestion. In the previous study, a locus in the center of gravity （stabilogram） was converted to values of statistical indices such as area of sway, total locus length, sparse density, and locus length per unit area, although these indices could not always distinguish between the stabilograms sampled from seven healthy young males in sober and intoxicated states. This measurement was made with an AMTI force plate. In this study, ＂translation error＂ was estimated in a d-dimensional embedding space in order to compare stabilograms recorded before and after the ingestion of doubly diluted brandy in 30 s （1 ≤ d ≤ 10）. The authors succeeded in validating stochastic differential equations as a mathematical model of the body sway. Although the postural control system shows different patterns in the lateral and anterior-posterior directions, the randomness in the model was preserved after alcohol intake and significantly increased in the medial/lateral direction. Visual information referred by the postural conlrol system when standing might be interfered by the effects of intoxication, which was regarded as disturbance. The possibility of detecting alcohol-ingestion-induced reduction of the equilibrium function and its recovery process are also suggested in this paper. This method is considered to be useful to diagnose the disorders of the vestibulo-cerebellar system.展开更多
This paper extends a prediction model for multi-directional random wave transformation based on an energy balance equation by Mase with the consideration of wave shoaling, refraction, diffraction, reflection and break...This paper extends a prediction model for multi-directional random wave transformation based on an energy balance equation by Mase with the consideration of wave shoaling, refraction, diffraction, reflection and breaking. This numerical model is improved by 1) introducing Wen's frequency spectrum and Mitsuyasu's directional function, which are more suitable to the coastal area of China; 2) considering energy dissipation caused by bottom friction, which ensures more accurate results for large-scale and shallow water areas; 3) taking into account a non-linear dispersion relation. Predictions using the extended wave model are carried out to study the feasibility of constructing the Ai Hua yacht port in Qingdao, China, with a comparison between two port layouts in design. Wave fields inside the port for different incident wave directions, water levels and return periods are simulated, and then two kinds of parameters are calculated to evaluate the wave conditions for the two layouts. Analyses show that Layout I is better than Layout II. Calculation results also show that the harbor will be calm for different wave directions under the design water level. On the contrary, the wave conditions do not wholly meet the requirements of a yacht port for ship berthing under the extreme water level. For safety consideration, the elevation of the breakwater might need to be properly increased to prevent wave overtopping under such water level. The extended numerical simulation model may provide an effective approach to computing wave heights in a harbor.展开更多
The use of satellite thermal infrared information is being developed as a method of exploring current tectonic activity. To realize real world application, an objective, stable and testable thermal physical index that...The use of satellite thermal infrared information is being developed as a method of exploring current tectonic activity. To realize real world application, an objective, stable and testable thermal physical index that is simultaneously related with tectonic activity must be established. From the viewpoint of the energy balance, the land surface is a boundary where energy is exchanged between outer space and the solid Earth. Regardless of how complex the influencing factors are, the land surface is mainly affected by the Sun, atmosphere and underground heat. In this paper, first, the relationships among land surface temperature, solar radiation, atmospheric temperature and thermal information from underground are obtained employing a mathematic physical method based on the equation of heat conduction and energy balance at the land surface. Second, a thermal physical index called the geothermal flux index (GFI), which can provide the activity state of underground heat, is constructed. Third, the theoretical basis of the thermal physical index is verified using stable annual variations in land surface temperature and solar radiation. Finally, combined with known crustal deformations derived using a global positioning system, the effectiveness of the GFI in extracting field tectonic motion is tested. The results indicate that the GFI is effective in providing information on current tectonic activity.展开更多
To get the actual ultimate bearing capacity of concrete dam, the effect of geometric nonlinearity and strain softening on it, which appears in the failure process of concrete dam, is studied. Overload method is adopte...To get the actual ultimate bearing capacity of concrete dam, the effect of geometric nonlinearity and strain softening on it, which appears in the failure process of concrete dam, is studied. Overload method is adopted to obtain the bearing capacity of a concrete dam by taking into consideration strain softening in the material constitutive law, geometric nonlinearity in geometric equation and equilibrium differential equation. Arc-length method is used to find the extreme point and descending branch of the load-displacement curve of the dam. The results present that the effect cannot be ignored. And geometric nonlinearity of structure and strain softening of materials should be considered for numerical analysis of ultimate bearing capacity of a concrete dam.展开更多
文摘Equilibrium function in the cerebellum （vestibulo-cerebellar system） can deteriorate under the influence of alcohol. In the Romberg posture, the center of gravity, which was measured every 50 ms by stabilometry, appeared to shift with alcohol ingestion. In the previous study, a locus in the center of gravity （stabilogram） was converted to values of statistical indices such as area of sway, total locus length, sparse density, and locus length per unit area, although these indices could not always distinguish between the stabilograms sampled from seven healthy young males in sober and intoxicated states. This measurement was made with an AMTI force plate. In this study, ＂translation error＂ was estimated in a d-dimensional embedding space in order to compare stabilograms recorded before and after the ingestion of doubly diluted brandy in 30 s （1 ≤ d ≤ 10）. The authors succeeded in validating stochastic differential equations as a mathematical model of the body sway. Although the postural control system shows different patterns in the lateral and anterior-posterior directions, the randomness in the model was preserved after alcohol intake and significantly increased in the medial/lateral direction. Visual information referred by the postural conlrol system when standing might be interfered by the effects of intoxication, which was regarded as disturbance. The possibility of detecting alcohol-ingestion-induced reduction of the equilibrium function and its recovery process are also suggested in this paper. This method is considered to be useful to diagnose the disorders of the vestibulo-cerebellar system.
基金supported by the National Natural Science Foundation of China (50879085)the Program for New Century Excellent Talents in University(NCET-07-0778)Fundamental Research Funds for the Central Universities (2012QNA4020)
文摘This paper extends a prediction model for multi-directional random wave transformation based on an energy balance equation by Mase with the consideration of wave shoaling, refraction, diffraction, reflection and breaking. This numerical model is improved by 1) introducing Wen's frequency spectrum and Mitsuyasu's directional function, which are more suitable to the coastal area of China; 2) considering energy dissipation caused by bottom friction, which ensures more accurate results for large-scale and shallow water areas; 3) taking into account a non-linear dispersion relation. Predictions using the extended wave model are carried out to study the feasibility of constructing the Ai Hua yacht port in Qingdao, China, with a comparison between two port layouts in design. Wave fields inside the port for different incident wave directions, water levels and return periods are simulated, and then two kinds of parameters are calculated to evaluate the wave conditions for the two layouts. Analyses show that Layout I is better than Layout II. Calculation results also show that the harbor will be calm for different wave directions under the design water level. On the contrary, the wave conditions do not wholly meet the requirements of a yacht port for ship berthing under the extreme water level. For safety consideration, the elevation of the breakwater might need to be properly increased to prevent wave overtopping under such water level. The extended numerical simulation model may provide an effective approach to computing wave heights in a harbor.
基金supported by National Natural Science Foundation of China (Grant No. 40902095)Basic Research Funds from the Institute of Geology, China Earthquake Administration (Grant No. DF-IGCEA-0608-2-6)the State Key Laboratory of Earthquake Dynamics (Project No. LED2009A07)
文摘The use of satellite thermal infrared information is being developed as a method of exploring current tectonic activity. To realize real world application, an objective, stable and testable thermal physical index that is simultaneously related with tectonic activity must be established. From the viewpoint of the energy balance, the land surface is a boundary where energy is exchanged between outer space and the solid Earth. Regardless of how complex the influencing factors are, the land surface is mainly affected by the Sun, atmosphere and underground heat. In this paper, first, the relationships among land surface temperature, solar radiation, atmospheric temperature and thermal information from underground are obtained employing a mathematic physical method based on the equation of heat conduction and energy balance at the land surface. Second, a thermal physical index called the geothermal flux index (GFI), which can provide the activity state of underground heat, is constructed. Third, the theoretical basis of the thermal physical index is verified using stable annual variations in land surface temperature and solar radiation. Finally, combined with known crustal deformations derived using a global positioning system, the effectiveness of the GFI in extracting field tectonic motion is tested. The results indicate that the GFI is effective in providing information on current tectonic activity.
基金supported by the National Basic Research Program of China ("973" Program) (Grant No. 2007CB714104)the National Natural Science Foundation of China (Grant Nos. 51079045 and 50779009)
文摘To get the actual ultimate bearing capacity of concrete dam, the effect of geometric nonlinearity and strain softening on it, which appears in the failure process of concrete dam, is studied. Overload method is adopted to obtain the bearing capacity of a concrete dam by taking into consideration strain softening in the material constitutive law, geometric nonlinearity in geometric equation and equilibrium differential equation. Arc-length method is used to find the extreme point and descending branch of the load-displacement curve of the dam. The results present that the effect cannot be ignored. And geometric nonlinearity of structure and strain softening of materials should be considered for numerical analysis of ultimate bearing capacity of a concrete dam.
