WRIST FORCE SENSOR'S DYNAMIC PERFORMANCE CALIBRATION BASED ON NEGATIVE STEP RESPONSE

Negative step response experimental method is used in wrist force sensor＇s dynamic performance calibration. The exciting manner of negative step response method is the same as wrist force sensor＇s load in working. This experimental method needn＇t special experiment equipments. Experiment＇s dynamic repeatability is good. So wrist force sensor＇s dynamic performance is suitable to be calibrated by negative step response method. A new correlation wavelet transfer method is studied. By wavelet transfer method, the signal is decomposed into two dimensional spaces of time-frequency. So the problem of negative step exciting energy concentrating in the low frequency band is solved. Correlation wavelet transfer doesn＇t require that wavelet primary function be orthogonal and needn＇t wavelet reconstruction. So analyzing efficiency is high. An experimental bench is designed and manufactured to load the wrist force sensor orthogonal excitation force/moment. A piezoelectric force sensor is used to setup soft trigger and calculate the value of negative step excitation. A wrist force sensor is calibrated. The pulse response function is calculated after negative step excitation and step response have been transformed to positive step excitation and step response. The pulse response function is transferred to frequency response function. The wrist force sensor＇s dynamic characteristics are identified by the frequency response function.

Analysis of the relationship between water level fluctuation and seismicity in the Three Gorges Reservoir(China)

The Three Gorges Reservoir is a good site for the further researches on reservoir induced seismicity due to decades＇ seismic monitoring. After the first water impounding in 2003, seismic activity becomes more frequent than that before water impoundment. In order to quantitatively study, the relationship between the water level fluctuation and earthquakes in TGR, we introduced statistical methods to attain the goal. First of all, we relocated the earthquakes in TGR region with double difference method and divided the earthquakes into 5 clusters with clustering analysis method. Secondly, to examine the impacts of water level fluctuation in different water filling stages on the seismic activity in the 5 clusters, a series of statistical analyses are applied. Pearson correlation results show that only the 175 m water level fluc- tuation has significantly positive impacts on the seismic activity in clusters I, II, III and V with correlation coefficients of 0.44, 0.38, 0.66 and 0.63. Cross-correlation analysis demonstrates that 0, ], 0 and 0 month time delay separately for the clusters I, II, III and V exists. It illustrated the influences of the water loading and pore pressure diffusion on induced earthquakes. Cointegration tests and impulse response analysis denoted that the 175 m water level only had long term and significant effects just on the seismic events in the intersection region of the Fairy Mount Fault and Nine-brook Fault. One standard deviation shock to 175 m water level increased the seismic activity in cluster V for the first 3 months, and then the negative influence was shown. After 7 months, the negative impulse response becomes stable. The long-term effect of the 175 m water impoundment also proved the important role of pore pressure diffusion in RIS with time.

Evaluation of the Genetic Relationship between Longevity and Growth, Milk Yield and Fertility Traits in the Sahiwal Breed in Kenya

Direct selection for longevity results in improved health and fitness and even milk production of cows. However, longevity is lowly heritable and phenotypic information is obtained at the end of an animal’s life. Traits expressed early in life and which are favorably correlated to longevity can be useful in selecting for this trait. The aim of this study was to estimate genetic correlations between longevity and age at first calving, first lactation calving interval, number of services per conception, first lactation milk yield, and first parity lactation length. Heritability estimates for measures of longevity were also calculated. The measures of longevity were time between birth and last milking in days (Long1), time between first calving and last milking record in months (Long2), number of lactations initiated (Long3), and total number of days in lactation over all lactations (Long4), total milk yield over all lactations (kg) (Long5). A series of five-variate animal models were fitted to estimate the nature and magnitude of genetic and phenotypic correlations between each measure of longevity and the fertility and production traits. Genetic correlations between measures of longevity and age at first calving, calving interval and number of services per conception were negative ranging from -0.14 ± 0.05 to -0.96 ± 0.06, -0.06 ± 0.03 to -0.67 ± 0.08 and -0.02 ± 0.02 to -0.73 ± 0.34, respectively. Correlations between measures of longevity and first lactation milk yield ranged from 0.88 ± 0.01 to 0.97 ± 0.03. Those with first parity lactation length ranged from -0.10 to 0.72. Long1, Long4 and Long5, which measure time between birth and last milking day, total number of days in lactation over all lactations and total milk yield over all lactations (kg), respectively, had the highest heritability estimates. These three could therefore be used to directly select for longevity. Among the traits studied, first lactation milk yield and age at first calving had the highest genetic correlation with measures of longevity. Therefore, first lactation milk yield and age at first calving could, therefore, be used to indirectly select for longevity.

Optimization of vinegar-steaming process for Wuweizi (Fructus Schisandrae Chinensis) with response surface method

OBJECTIVE:To optimize the vinegar-steaming process of Wuweizi(Fructus Schisandrae Chinensis)using the response surface method(RSM)based on the Box-Behnken design.METHODS:A regression model was constructed with the response variables,the content of Deoxyschizandrin,and the three explanatory factors:length of steaming time,the quantity of vinegar and length of moistening time to evaluate the effects on the processing of Wuweizi(Fructus SchisandraeChinensis).RESULTS:There was a linear relationship between the content of Deoxyschizandrin and the three explanatory factors.When the steaming time was5.49 h,with 2.365 g of vinegar added and a moistening time of 4.13 h,the content of Deoxyschizandrin reached the maximum predicted value of0.1076%,and under the conditions the average content of Deoxyschizandrin was 0.1058%.CONCLUSION:The correlation coefficient of thenonlinear mathematical model was relatively high and the model matched the data well,potentially providing a method for the study of the steaming process.