... on the null hypothesis α = whereas if it is less than the data are in support of the null hypothesis3 To determine how big | tα=0 | needs to be to reject the null, we use the fact that under the ... included in the regression The standard deviation of the residuals is essentially equal to the standard error of the regression - the difference being due to the fact that the formula for the standard ... Notice that the histogram of returns on the market are heavily skewed left whereas the histogram for IBM is much more sysingle index modeletric about the mean Also, the kurtosis for the market...
Ngày tải lên: 17/12/2013, 15:17
... measure of overall variability of the data points along the X – axis Therefore, the higher value of hi the higher is the leverage of the ith data point, the greater the distance of Xi from its mean ... n n ∑ (Xi − X ) i =1 The additional term in the denominator, − h i , is necessary since the variance of the residuals is assumed not to be constant With the adjustment factor, we get a t – statistic, ... of leverage of the ith data point It measures leverage because the numerator is the squared distance of the ith data point from its mean in the X – direction, while its denominator is a measure...
Ngày tải lên: 27/01/2014, 11:20
Tài liệu Báo cáo khoa học: "Fast and Robust Part-of-Speech Tagging Using Dynamic Model Selection" pptx
... the CNN broadcasting news (BN), the Sinorama news magazine (MZ), the WSJ newswire (NW), and the G ALE web-text (WB), all from OntoNotes v4.0 Additionally, the Mipacq clinical notes (CN) and the ... distributions of these evaluation sets 4.2 Accuracy comparisons Our models are compared with two other state-ofthe-art systems, the Stanford tagger (Toutanova et al., 2003) and the SVMTool (Gim´ nez ... other model) For both all and unknown token experiments, Model S performs better than the other systems when evaluated on a mixture of the data (the Total column) The differences are statistically...
Ngày tải lên: 19/02/2014, 19:20
Báo cáo khoa học: "A Bag of Useful Techniques for Efficient and Robust Parsing" ppt
... are combined, the parser has to unify the feature structure of the passive item into the substructure of the active item that corresponds to the argument to be filled If either of the two structures ... before, the parser associates with it a vector of length n containing the types at the end of the previously determined paths The first position of the vector contains the type corresponding to the ... due to the following fact: if the GLB of s and t is bottom, we not have to compute the GLBs of the subtypes of both s and t, since t h e y guarantee to fail Even with these improvements, the...
Ngày tải lên: 08/03/2014, 06:20
design of simple and robust process plants
... something goes wrong, the unit may shut down automatically, while maintenance person next to the operator has remote access to the system in order to diagnose the cause of the failure The operation of ... point of view, the techniques to deal with these situations are available The key is the mind set to evaluate this also for other situations 1.3.8 Design for Total Quality Control (TQC) The concept ... order to enable the design The instruments are the eyes, ears, and hands of the process, and special emphasis must be given to them Firstly, they need to be measuring correctly what we want to measure...
Ngày tải lên: 02/04/2014, 16:24
báo cáo sinh học:" Workforce analysis using data mining and linear regression to understand HIV/AIDS prevalence patterns" pdf
... affected the results The first step was to eliminate them from the sample, one by one The second step considered recalculating new cluster values The third step assessed whether the nodes and their ... nurses to ensure that they not fall victims to the disease they help to prevent through occupational exposure Concurrently, there will have to be multi-sectoral efforts to improve the status of women ... However, in addition to the provision of anti-retroviral medications, there are additional health system factors that may influence the achievement of the MDGs One of these factors is the health care...
Ngày tải lên: 18/06/2014, 17:20
home energynmanagement problem towards an optimal and robust solution
... uncertain region into two critical regions The first region corresponds to the zone: −5 ≤ Text ≤ −0.875 The optimal solution is to put the heater to the maximum level in order to approach the desired ... energy is assigned to the radiator In fact, Text = −0.875 is the point of the system where the maximum power generated by the radiator can compensate the thermal flow lost through the building envelope ... inhabitants care about their cost and their environmental impact These two aspects have to be assessed In most cases, the economical criterion corresponds to the cost of the provided, stored or sold...
Ngày tải lên: 27/07/2014, 23:29
Automatic spike sorting and robust power line interference cancellation for neural signal processing
... forgetting factor λ0 Initial forgetting factor of the frequency estimator λst Rate of change from λ0 to λ∞ λ∞ Asymptotic forgetting factor of the frequency estimator xv λa Forgetting factor of the amplitude/phase ... determines the asymptotic notch bandwidth and αst sets the rate of change from the initial value αf (0) = α0 to the asymptotic value α∞ Similarly, λ∞ determines the asymptotic forgetting factor and ... practice, the drifts in the power line frequency are usually slow and the algorithm can still reasonably track the variations The forgetting factor of the frequency estimator λf is initially small to...
Ngày tải lên: 09/09/2015, 08:12
An integrated process planning and robust fixture design system 1
... analyzed and the mathematical model to calculate the point-wise localization error is established The distance of the location points among the locators is taken into account to ensure the location ... and the mathematical model to calculate the pointwise localization error is established The distance of the location points among the Chapter Introduction locators is taken into account to ensure ... design The term fitness is used to designate the chromosome’s chances of survival, and it is essentially the objective function of the optimization problem The genetic algorithms have been proven to...
Ngày tải lên: 11/09/2015, 09:16
An integrated process planning and robust fixture design system 2
... comparison of the tolerance relations between the different shape elements of the part A tolerance factor has been developed to compare the effect of different tolerances The system selects the positioning ... Objectives To minimize the magnitude of perturbation at the workpiece’s mass center caused by the locators To minimize the norm of the grasp forces To minimize the workpiece positional errors To minimize ... errors by minimizing the magnitude of perturbation at the workpiece’s mass center caused by the locators In their method, the determinant of the locator matrix was used as the optimization objective...
Ngày tải lên: 11/09/2015, 09:16
An integrated process planning and robust fixture design system 3
... completely, the feedback to the MM is negative Otherwise, the feedback is positive with a minimum cost value, together with the corresponding optimal set-up plan The MM then asks the selected MTMs in the ... and the TOS of the candidates of the machine resources During the tolerance planning stage, machining features are grouped into set-ups based on the machine tools assigned and their TADs, and the ... sections To ensure the fixturing features can be blended to the existing dimensions of these castings, they are to be parametrically defined, and their sizes can be varied according to the different...
Ngày tải lên: 11/09/2015, 09:16
An integrated process planning and robust fixture design system 4
... so the system prompts the designer to input the two values in the part level and they are applied to all cast surfaces For machined surfaces, the designer needs to select the specific surface to ... based on the sketch As the sketch lies on the sketch plane, therefore, the TAD of the machining feature is parallel to the sketch plane’s normal direction For the through holes B and C, there are ... the tool approach direction (TAD) needs to be considered together with the sketch plane direction A surface with the normal direction parallel with the normal direction of the sketch plane but the...
Ngày tải lên: 11/09/2015, 09:16
An integrated process planning and robust fixture design system 5
... space Tool selection is based on the TAD of the machining feature and the TOS of available machine tools The TAD of the machining feature must be inside the TOS of the selected machine tool The ... on their TADs and the TOSs from the available machine resources During the tolerance planning stage, the machining features are grouped into set-ups based on the machine tool assigned and their ... set-up The set-up change cost and the cutter change cost is based on the change times The transport cost depends on the distance of the current machine to the next machine Therefore, the cost...
Ngày tải lên: 11/09/2015, 09:16
An integrated process planning and robust fixture design system 6
... distance of the solution in the Pareto set; : is the locating error of the solution in the Pareto set; : is the deviation of the locating errors of the solution in the Pareto set; i: is the selected ... the Pareto optimal set as follows: : 1⁄ 1 (6.9) is the average locating distance of the solutions in the Pareto set; : is the average locating error of the solutions in the Pareto set; : is the ... generation of the algorithm involves ants moving from a start node to the final node to construct a complete tour The tour includes two selection levels One is on the face level, the other is on the nodes...
Ngày tải lên: 11/09/2015, 09:16
An integrated process planning and robust fixture design system 7
... as tolerance, datum together, thus it can capture the designer’s intent This approach takes into account the dimensional tolerances and positioning accuracy of the workpiece in relation to ... model is used to optimize the set-up planning process Both dimension and position tolerance requirements are taken into account and a tolerance cost factor is introduced to consider the compression ... work to solve the multi-objective fixture layout problem, i.e., to maximize the distance of the 144 Chapter Conclusions and Future Works location points, to minimize the localization errors and the...
Ngày tải lên: 11/09/2015, 09:16
An efficient and robust algorithm for incompressible flow and its application in heat transfer enhancement
... in the front part of the fins due to the developing boundary layers as well as in front of the tube due to a vortex system there On the other hand, for the portion of the fin associated with the ... because their fins were electrically heated, the thermocouples were embedded in the plate to determine the plate surface temperature, and the power to the several electric heaters was adjusted to ... 2002a), and they also recommended that the enhancement techniques should be adopted mainly in the rear part of the fin surface to enhance the convective heat transfer further With the computational...
Ngày tải lên: 11/09/2015, 16:02
Comprehensive modeling and robust nonlinear control of HDD servo systems
... location Rotational latency is the average time (in milliseconds) the R/W heads must wait for the target sector on the disk to pass under them once the R/W heads are moved to the desired target track ... System) micro-actuator Dual-stage servo design aims to use the two different actuators to their advantages, so as to enhance the combined performance It is important to make sure that there is no destructive ... law on top of the linear law to increase the damping ratio of the closed-loop system at steady state and hence reduce the overshoot caused by the linear part An integrator will be added to the overall...
Ngày tải lên: 15/09/2015, 22:15
Forecasting creditworthiness in retail banking a comparison of cascade correlation neural networks, CART and logistic regression scoring models
... uncertainty Tontines have some drawbacks as credit tools They can only be used for the short-term as the debt will have to be repaid at the end of the Tontine‟s cycle; the interest on Tontine credit ... essential to establishing and monitoring the creditworthiness of borrowers in the joint interests of themselves and their lenders The credit scoring system of choice needs to be tailored to the particular ... (Fahlman, 1988) to minimize the error‟ When no further improvement is seen in the level of error, the network‟s performance is evaluated If the error is small enough, the network stops Otherwise a...
Ngày tải lên: 26/09/2015, 12:03