The objective of this study was to determine lactation performance responses of high-producing dairy cows to a reduced-starch diet compared with a normal-starch diet and to the addition of exogenous amylase to the reduced-starch diet. Thirty-six multiparous Holstein cows (51 ± 22 DIM and 643 ± 49 kg of body weight at trial initiation) were randomly assigned to 1 of 3 treatments in a completely randomized design: a 3-wk covariate adjustment period during which the cows were fed the normal-starch diet, followed by a 12-wk treatment period during which the cows were fed their assigned treatment diets. The normal-starch TMR did not contain exogenous amylase (NS−). The reduced-starch diets, formulated by partially replacing corn grain with soy hulls, were fed without (RS−) and with (RS+) exogenous amylase added to the TMR. Starch and NDF concentrations averaged 27.1 and 30.6%, 21.8 and 36.6%, and 20.7 and 36.6% (dry matter basis) for the NS−, RS−, and RS+ diets, respectively. Dry matter intake for cows fed the RS− diet was 2.4 and 3.2 kg/d greater than for cows fed the NS− and RS+ diets, respectively. Intake of NDF ranged from 1.19 to 1.52% of body weight among the treatments, with the RS− diet being 28% greater than the NS− diet and 13% greater than the RS+ diet. Milk yield averaged 50.4 kg/d and was unaffected by treatment. Fat-corrected milk yield was 2.9 kg/d greater for cows fed the RS− diet than for cows fed the NS− diet. Body weight and body condition score measurements were unaffected by treatment. Fat-, solids-, and energy-corrected milk feed conversions (kilograms/kilogram of DMI) were 12 to 13% greater for cows fed the RS+ diet than for cows fed the RS− diet. Dry matter and nutrient digestibilities were lowest for cows fed the NS− diet and greatest for cows fed the RS+ diet, and were greater for cows fed the RS+ diet than for cows fed the RS− diet, with the exception of starch digestibility, which was similar. Greater conversion of feed to milk for dairy cows fed reduced-starch diets that include exogenous amylase may offer potential for improving economic performance. 相似文献
This paper presents a wavelet norm entropy-based effective feature extraction method for power quality (PQ) disturbance classification problem. The disturbance classification schema is performed with wavelet-neural network (WNN). It performs a feature extraction and a classification algorithm composed of a wavelet feature extractor based on norm entropy and a classifier based on a multi-layer perceptron. The PQ signals used in this study are seven types. The performance of this classifier is evaluated by using total 2800 PQ disturbance signals which are generated the based model. The classification performance of different wavelet family for the proposed algorithm is tested. Sensitivity of WNN under different noise conditions which are different levels of noises with the signal to noise ratio is investigated. The rate of average correct classification is about 92.5% for the different PQ disturbance signals under noise conditions. 相似文献
This paper describes a combined theoretical and experimental study of thermal comfort during the heating period inside an automobile. To investigate the effects of thermal conditions on the human physiology and thermal comfort during the heating period, temperature, humidity and air velocity were measured at a number of points inside the automobile, so thermal conditions were accurately determined. The human body was divided into 16 sedentary segments, and the change of temperature was observed both experimentally and theoretically. During transient conditions of the heating period, heat and mass transfer between the human body and the interior environment of an automobile were simulated by a computational model, and predictions were compared with the measured data. It is shown that there is a good agreement between the model predictions and experimental results. By means of the present model, the effects of the fast transient conditions of the heating period on the sensible and latent heat transfer from the body, body segments skin temperatures and thermal sensation were investigated in detail. 相似文献
In this paper, a different cryptographic method is introduced by using a Power series transform. A new algorithm for cryptography is produced. The extended Laplace transform of the exponential function is used to encode an explicit text. The key is generated by applying the modular arithmetic rules to the coefficients obtained in the transformation. Here, ASCII codes used to hide the mathematically generated keys to strengthen the encryption. Text steganography is used to make it difficult to break the password. The made encryption is reinforced by image steganography. To hide the presence of the cipher text, it is embedded in another open text with a stenography method. Later, this text is buried in an image. For decryption, it is seen that the inverse of the Power series transform can be used for decryption easily. Experimental results are obtained by making a simulation of the proposed method. As a result, it is stated that the proposed method can be used in crypto machines.
The importance of the research on insulator pollution has been increased considerably with the rise of the voltage of transmission lines. In order to determine the flashover behavior of polluted high voltage insulators and to identify to physical mechanisms that govern this phenomenon, the researchers have been brought to establish a modeling. In this paper, a dynamic model of AC flashover voltages of the polluted insulators is constructed using the least square support vector machine (LS-SVM) regression method. For this purpose, a training set is generated by using a numerical method based on Finite Element Method (FEM) for several of common insulators with different geometries. To improve the resulting model’s generalization ability, an efficient optimization algorithm known as the grid search are adopted to tune parameters in LS-SVM design.In addition, two different testing set, which are not introduced to the LS-SVM during the training procedures, is used to evaluate the effectiveness and feasibility of the proposed method. Then, optimum LS-SVM model is firstly obtained and the performance of the proposed system with other intelligence method based on ANN is compared. It can be concluded that the performance of LS-SVM model outperforms those of ANN, for the data set available, which indicates that the LS-SVM model has better generalization ability. 相似文献
The pollution flashover, observed on insulators used in high voltage transmission, is one of the most important problems for power transmission. It is a very complex problem due to several factors such as the modeling difficulties of complex shapes of the insulators, different pollution density at different regions, non-homogeneous pollution distribution on the insulator surface and unknown effect of humidity on the pollution. In the literature, some static and dynamic models were developed by making some assumptions and omissions to predict the flashover voltages of polluted insulators. In this study, historical development of insulator modeling was investigated and a dynamic arc model was proposed. For this purpose, scaled shape of a concerned insulator was firstly partitioned into triangular elements, then finite element method (FEM) was implemented and finally potential distribution on the insulator surface, variation of pollution resistance and flashover voltage were determined. The computed flashover voltage values of the selected string insulator have been compared to results from other research. 相似文献
The performances of porous bearings under different operating conditions were experimentally investigated in this study. Material
groups studied are 90%Cu+10%Sn bronze and 1%C + % balance Fe iron-based self-lubricating P/M bearings at constant (85%) density.
In the experiments, the variation of the coefficient of friction and wear ratio of those two different group materials for
different sliding speeds, loads, and temperatures were investigated. As a result, the variation of the friction coefficient
- temperature for both constant load, and constant sliding speed, friction coefficient - average bearing pressure, PV - wear
loss and temperature-wear loss curves were plotted and compared with each other for two materials, separately. The test results
showed that Cu-based bearings have better friction and wear properties than Fe-based bearings. 相似文献
Marmaray immersed tube crossing, located at the entrance of Bosphorus Strait of Istanbul, will be one of the unique infrastructure facility bringing great engineering challenges in immersed tunnel technology. The employer requires a minimum design life of 100 years for the immersed tunnel structure that will be under exposure of the highest saline water pressure at the depth of 58 m that has never been experienced yet in the history of immersed tube systems. Since the structural concrete is to be subjected to extremely aggressive environmental conditions during expected long-term service life, the quality assurance of the immersed tunnel has been ensured by setting a series of effective technical requirements taking into account the potential durability risks and predictive models in design phase, outputs of pre-testing activities and potential difficulties at construction period. The objective of this paper is to present some major steps involved in concrete works of this megaproject by giving the highlights from laboratory scale researches to the execution of the work at construction site. 相似文献