factors that influence the appearance of tumors in images

... shapes The RCS of real aircraft must be measured It varies significantly depending upon the direction of the illuminating radar 4-11.2 Figure shows a typical RCS plot of a jet aircraft The plot ... aspect (increasing reflectivity) The next highest RCS area is the nose/tail area, largely because of reflections off the engines or propellers Most self-protection jammers cover a field of view of ... example is 100 m2 in the beam, and the weakest is slightly more than m2 in the 135E/225E positions These RCS values can be very misleading because other factors may affect the results For example,...

Ngày tải lên: 08/11/2013, 19:15

... denote the position of the centroid of the plane lamina of Figure 8.2 At the centroid the moment of area is zero, so that the following equations apply Z x dA = Z y d A = dA = elemental area of the ... as theperpendicular axes theorem which states that the sum of the second moments of area of two mutually perpendicular axes of a lamina is equal to the polar second moment of area about a point ... second moment of area about x-x In = the second moment of area about X-X The importance of the parallel axes theorem is that it is useful for calculating second moments of area of sections of RSJs,...

Ngày tải lên: 08/04/2014, 11:28

... denotes the length of the sliding window and it is the sum of the number of detections (N), and the number of misses (M) in the window Note that the function (14) corresponds to an average of the ... number of detections in the window On the contrary, the window size of ML(N = n) can change to retain n detections in the window The average SNR, SNR, was set to a constant having a value of 8, ... estimates of σ that are obtained based on the observations of the detections and misses in the window To be more specific, (zi − 1)/αi in the first term of (14) is an (one-sample) unbiased estimate of...

Ngày tải lên: 21/06/2014, 08:20

... respectively, R0 is the intersection point of the circles and X-axes The motion of the charged particle in the plane of cross section is localized in the dashed area as it is shown in Fig 1b In the strong ... by the fact that the Taylor expansion of potential (17) for small values of the x-coordinate is parabolic as it is the case for (12) also On the other hand, at higher values of the ¨ x-coordinate ... quantum number When the coordinate of the ‘‘slow’’ subsystem, x, is fixed, the motion of the electron is localized in the onedimensional effective potential well, having the following spatial profile:...

Ngày tải lên: 22/06/2014, 01:20

... described in the text; others cover new ideas that can be analyzed using the tools presented in the current and previous chapters Several of the problems require using the data sets that are included ... basis The book contains proofs or outlines the proofs of many assertions, focusing on the role played by the assumptions with economic content while downplaying or ignoring regularity conditions The ... Models Introduction The Linear Probability Model for Binary Response Index Models for Binary Response: Probit and Logit Maximum Likelihood Estimation of Binary Response Index Models Testing in Binary...

Ngày tải lên: 06/07/2014, 08:20

... studying the e¤ect of w on the expected value of y The reason we control for these variables is that we think w is correlated with other factors that also in uence y If w is continuous, interest ... regardless of how they are related to the xi Assuming that the population mean of the error is zero is without loss of generality when an intercept is included in the model Thus, the statement ‘ The ... binary variable indicating marital status The variable u, called the error term or disturbance, contains unobserved factors that a¤ect the wage o¤er Interest lies in the unknown parameters, the...

Ngày tải lên: 06/07/2014, 08:20

... treated in the same framework because they are linear in the parameters bj The fact that equation (2.3) is nonlinear in x has important implications for interpreting the bj , but not for estimating ... density of y given x by integration, summation, or a combination of the two (depending on the nature of y) It follows that the conditional expectation operator has the same linearity properties as the ... for relating the two expectations Obtaining E½m1 ðx; zÞ j xŠ generally requires integrating (or summing) m1 ðx; zÞ against the conditional density of z given x, but in many cases the form of Eðy...

Ngày tải lên: 06/07/2014, 08:20

... find the limiting distribution of many interesting functions of xN This is especially useful for determining the asymptotic distribution of test statistics once the limiting distribution of an ... continuous function, then gðxN Þ ! gðxÞ The usefulness of Lemma 3.6, which is called the continuous mapping theorem, cannot be overstated It tells us that once we know the limiting distribution of ... continuous at plim xN Slutsky’s theorem is perhaps the most useful feature of the plim operator: it shows that the plim passes through nonlinear functions, provided they are continuous The expectations...

Ngày tải lên: 06/07/2014, 08:20

... e¤ects of the observed explanatory variables holding the other explanatory variables constant, including the unobservable q In the context of this additive model, there is no point in allowing for ... context of models that are linear in the parameters under random sampling, identi- The Single-Equation Linear Model and OLS Estimation 53 fication of b simply means that b can be written in terms of ... correlated Of course, these are just the findings from one sample Adding IQ explains only one percentage point more of the variation in logðwageÞ, and the equation predicts that 15 more IQ points (one...

Ngày tải lên: 06/07/2014, 08:20

... define the linear combination of interest, say y a1 b1 þ a2 b2 þ Á Á Á þ aK bK , and then to write one of the bj in terms of y and the other elements of b Then, substitute into the equation of interest ... class of all instrumental variables estimators using instruments linear in z ^ ~ Proof: Let b be the 2SLS estimator, and let b be any other IV estimator using ~ ~ instruments linear in z Let the instruments ... violated (This reasoning assumes that we are interested in estimating the pure e¤ect of serving in Vietnam, as opposed to including indirect e¤ects such as reduced job training.) Instrumental Variables...

Ngày tải lên: 06/07/2014, 08:20

... industry, and type of injury These allow for the fact that the kind of people and type of injuries di¤er systematically in the two years Perhaps not surprisingly, controlling for these factors has little ... from the incinerator Is this regression appropriate for determining the causal e¤ects of incinerator on housing prices? Explain b Pooling the two years of data, consider the model Additional Single-Equation ... generated instruments The tools needed to make the proof rigorous are introduced in Chapter 12, but the key components of the proof can be given here in the context of the linear model Write the model...

Ngày tải lên: 06/07/2014, 08:20

... use a SUR software routine in obtaining the estimates: we may be interested in testing joint hypotheses involving parameters ^ in di¤erent equations In order to so we need to estimate the variance ... important consequences The most important of these is that, for performing asymptotic inference about b using ^ ^ b , we not have to worry that W is an estimator of W Of course, whether the asymptotic ... tending to in nity In the household demand example, we are interested in a set of three demand functions, and the unit of obser- Estimating Systems of Equations by OLS and GLS 145 vation is the...

Ngày tải lên: 06/07/2014, 08:20

... given in expression (8.26) The question is, Can we say that using the full set of instruments (with the optimal weighting matrix) is better than using the reduced set of instruments (with the optimal ... means that z and nonlinear functions of z are valid instruments in every equation 206 Chapter a Suppose that Eðxg j zÞ is linear in z for all g Show that adding nonlinear functions of z to the instrument ... obtained—by estimating the linear projection of xiK on zi in the first stage—it makes perfectly good sense that zi2 can be omitted under condition (8.54) without a¤ecting e‰ciency of 2SLS In the...

Ngày tải lên: 06/07/2014, 08:20

... estimation In plugging fitted values into equation (9.61), our mistake is in thinking that the linear projection of the square is the square of the linear projection What the 2SLS estimator does in the ... using the usual rank condition Adding equation (9.58) to the original system and then studying the rank condition of the first two equations is equivalent to studying the rank condition in the ... by 2SLS The bottom line is that the methods studied in Chapters and are directly applicable All of the tests we have covered apply, including the tests of overidentifying restrictions in Chapters...

Ngày tải lên: 06/07/2014, 08:20

... appearing in the structural equation to obtain the estimating equation, including any binary indicators indicating participation in the program The estimates should be interpreted in the orginal ... Estimation of the E¤ects of Job Training Grants): We now use the data in JTRAIN1.RAW to estimate the e¤ect of job training grants on firm scrap rates, using a random e¤ects analysis There are 54 firms that ... kinds of serial correlation in the composite error vit , and so a rejection of the null should not be interpreted as implying that the random e¤ects error structure must be true Finding that the...

Ngày tải lên: 06/07/2014, 08:20

... e¤ect ci contains cityspecific unobserved factors that can a¤ect sexual conduct, as well as the incidence of HIV Equation (11.8) is one way of capturing the fact that the spread of HIV is in uenced ... heteroskedasticity In the pure AR(1) model, using lags of yit as an instrument for Dyi; tÀ1 means that we are assuming the AR(1) model captures all of the dynamics If further lags of yit are added to the structural ... =sx à being important in determining the size of the measurement error bias, the à ratio ð1 À rr Þ=ð1 À rx Ã Þ is also important As the autocorrelation in xit increases rel^ increases In fact,...

Ngày tải lên: 06/07/2014, 08:20

... We introduce the subscript ‘‘o’’ on theta to distinguish the parameter vector appearing in Eðy j xÞ from other candidates for that vector (Often, the value yo is called ‘ the true value of theta,’’ ... assume that lo is in the interior of its parameter space, L, under H0 We also assume that d is twice continuously di¤erentiable on the interior of L ~ Let l be the solution to the constrained minimization ... results The general derivation of the LM statistic also assumed that y o A intðYÞ under H0 Nevertheless, for certain applications of the LM test we can drop the requirement that y o is in the interior...

Ngày tải lên: 06/07/2014, 08:20

... to assume the regularity conditions there; in particular, we assume that yo is in the interior of Y, and li ðy Þ is twice continuously di¤erentiable on the interior of Y The score of the log likelihood ... nðdzÞ Then ð pðy j xÞ ¼ pðy j x; zÞpðz j xÞnðdzÞ Z In other words, we can obtain the density of y given x by integrating the density of y given the larger conditioning set, ðx; zÞ, against the ... elements of any of the matrices We discussed each of these estimators in the general M-estimator case in Chapter 12, but a brief review is in order The first estimator, based on the Hessian of the...

Ngày tải lên: 06/07/2014, 08:20

... McFadden (1994, Theorem 3.4): theorem 14.2 (Asymptotic Normality of GMM): In addition to the assumptions in Theorem 14.1, assume that (a) yo is in the interior of Y; (b) gðw; ÁÞ is continuously di¤erentiable ... has a limit2 ing wQ distribution 14.3 Systems of Nonlinear Equations A leading application of the results in Section 14.2 is to estimation of the parameters in an implicit set of nonlinear equations, ... asymptotic) version of the Gauss-Markov theorem from linear regression analysis: while the Gauss-Markov theorem states that OLS has the smallest variance in the class of linear, unbiased estimators,...

Ngày tải lên: 06/07/2014, 08:20