direct and indirect visualization of tumors

... Reduction of RCS Affects Radar Detection, Burn-through, and Jammer Power Example of Effects of RCS Reduction - As shown in Figure 6, if the RCS of an aircraft is reduced to 0.75 (75%) of its original ... RCS of a sphere is independent of frequency) 0.001 0.1 10 1.0 2Br/8 B * “RF far field” equivalent Courtesy of Dr Allen E Fuhs, Ph.D Figure Radar Cross Section of a Sphere ADDITION OF SPECULAR AND ... reflecting elements and 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...

Ngày tải lên: 08/11/2013, 19:15

... 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, ... distance of dA from G y where = (8.1) vertical distance of dA from G Centroidal axes 8.3 These are the axes that pass through the centroid Second moment of area (I) 8.4 The second moments of area of ... moments of area of two mutually perpendicular axes of a lamina is equal to the polar second moment of area about a point where these two axes cross 8.5 Parallel axes theorem Consider the lamina of...

Ngày tải lên: 08/04/2014, 11:28

... 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 estimates of ... 0.81) Table shows that the errors of ML(N = 10) and ML(W = 15) are 0.278 and 0.273 for SNR = 16, respectively, and those of ML(N = 10) and ML(W = 12) are 0.290 and 0.297 for SNR = 32, respectively ... Signal and Data Processing of Small Targets, vol 2759 of Proceedings of SPIE, pp 418–428, Orlando, Fla, USA, April 1996 [3] G van Keuk and S S Blackman, “On phased-array radar tracking and parameter...

Ngày tải lên: 21/06/2014, 08:20

... radii of two circles of the cross section, respectively, 2c is height of the cylinder, L1, L2 are heights of cross section segments, respectively, R0 is the intersection point of the circles and ... radius of the electron (or the hole) We consider the case of a heavy hole, when me ( mh ; with me and mh being the effective masses of the electron and hole, respectively Under conditions of one-electron ... N and equal parity quantum numbers, N À N ¼ 2t: Partial reduction of number of selection rules in the case of falciform cross section of cylindrical-well QD is due to oscillatory character of...

Ngày tải lên: 22/06/2014, 01:20

... available in Volume of the Handbook of Econometrics—see Powell (1994) and Hardle and Linton (1994)—as well as in ¨ Volume 11 of the Handbook of Statistics—see Horowitz (1993) and Ullah and Vinod (1993) ... analysis Volume of the Handbook of Econometrics and Volume 11 of the Handbook of Statistics contain nice surveys of these topics (Hajivassilou and Ruud, 1994; Hall, 1994; Hajivassilou, 1993; and Keane, ... considerations almost always come after a large-sample analysis and are often done on a case-bycase basis The book contains proofs or outlines the proofs of many assertions, focusing on the role played by...

Ngày tải lên: 06/07/2014, 08:20

... saving of employees within a firm may be correlated because of common (often unobserved) characteristics of workers within a firm or because of features of the firm itself (such as type of retirement ... measures of the elements of c, we might not have very good measures of y or w A more subtle problem—which we study in detail in Chapter 9—is that we may only observe equilibrium values of y and w ... assumptions involving things such as the number of absolute moments of a random variable that must be finite.) For much of this book we adopt a random sampling assumption More precisely, we assume...

Ngày tải lên: 06/07/2014, 08:20

... 2.4 For random scalars u and v and a random vector x, suppose that Eðu j x; vÞ is a linear function of ðx; vÞ and that u and v each have zero mean and are uncorrelated with the elements of x Show ... expectation operator, and several additional properties that are consequences of the randomness of mðxÞ Some of the statements we make are proven in the appendix, but general proofs of other assertions ... book Suppose that w is a random vector and y is a random variable Let x be a random vector that is some function of w, say x ¼ fðwÞ (The vector x could simply be a subset of w.) This statement implies...

Ngày tải lên: 06/07/2014, 08:20

... square root of the appropriate diagonal ele^N ment of V =N The asymptotic standard errors can be loosely thought of as estimating ^ the standard deviations of the elements of yN , and they are ... Á op ð1Þ ¼ op ð1Þ All of the previous definitions apply element by element to sequences of random vectors or matrices For example, if fxN g is a sequence of random K Â random p p vectors, xN ! ... repeated application of Lemma 3.2 (see Problem 3.2) lemma 3.3: Let fZN : N ¼ 1; 2; g be a sequence of J Â K matrices such that ZN ¼ op ð1Þ, and let fxN g be a sequence of J Â random vectors such...

Ngày tải lên: 06/07/2014, 08:20

... square roots of the diagonal elements of equation (4.11) are often called the White standard errors or Huber standard errors, or some hyphenated combination of the names Eicker, Huber, and White ... same for x2 Find a1 and a2 in terms of the bj and mj b Rewrite the regression function so that a1 and a2 appear directly (Note that m1 and m2 will also appear.) c Given a random sample, what ... u u r ~ r by each element of ^ and SSR0 is just the usual sum of squared residuals from rer gression (4.17) Thus, we first regress each element of x2 onto all of x1 and collect the ~ r residuals...

Ngày tải lên: 06/07/2014, 08:20

... Þ=ðx1 À x0 Þ where y0 and x0 are the sample averages of yi and xi over the part of the sample with zi ¼ 0, and y1 and x1 are the sample averages of yi and xi over the part of the sample with zi ... quarters of birth and various interactions of these with year of birth and state of birth—are very weak, and they are too numerous relative to their contribution in explaining years of education ... 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 so that...

Ngày tải lên: 06/07/2014, 08:20

... elements of x i and xi0 x i : the levels, squares, and cross products of the regressors in the conditional mean The Breusch-Pagan and White tests have degrees of freedom that depend on the number of ... element of y y2 onto z) Now, let h2 be any  Q1 subset of z (It does not matter which elements of z we choose, as long as we choose Q1 of them.) Regress each element of h2 onto ðz1 ; ^2 Þ and collect ... estimators of b and g in the regression of yis on x is , zs are still unbiased if Eðqs j X s ; zs Þ ¼ 0, but consistency and asymptotic normality are tricky, because, with a small number of strata and...

Ngày tải lên: 06/07/2014, 08:20

... to infinity 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 family ... combination of Xi , and since each element of Xi is uncorrelated with each element of ui , any linear combination of Xi is uncorrelated with ui We can also show this directly using the algebra of Kronecker ... between males and females in both earnings and benefits But what about between whites and nonwhites, and married and unmarried people? The F-type statistic for joint significance of married and white...

Ngày tải lên: 06/07/2014, 08:20

... Linear System of Equations We now discuss estimation of a general linear model of the form yi ¼ Xi b þ u i ð8:11Þ where yi is a G Â vector, Xi is a G Â K matrix, and u i is the G Â vector of errors ... first-stage u ^ residuals ^i are used in place of ^ i The square roots of diagonal elements of this u u matrix are the asymptotic standard errors of the optimal GMM estimator This estimator is ... as nonrandom and Varðu i Þ is constant across i Because we are assuming random sampling, we are forced to properly focus attention on the variance of u i conditional on Zi For the system of equations...

Ngày tải lên: 06/07/2014, 08:20

... matrix R1 consists only of zeros and ones, and the number of rows in R1 equals the number of excluded right-hand-side endogenous variables, G À G1 À 1, plus the number of excluded exogenous variables, ... functions of z1 and z2 to the instrument list: the linear projection of y2 on z1 , z2 , and any function of ðz1 ; z2 Þ will only depend on z1 and z2 Equation (9.59) is an example of a poorly ... equation and noting that y1 is a linear function of z and u1 Then, in the second equation, y1 is uncorrelated with u2 under assumption (9.40) But y2 is a linear function of z, u1 , and u2 , and so...

Ngày tải lên: 06/07/2014, 08:20

... also the ratio of the variance of ci to the variance of the composite error, and it is useful as a measure of the relative importance of the unobserved e¤ect ci Assumptions (10.28) and (10.29) ... serial correlation in the fuit g, as this is a test of the random e¤ects form of W Baltagi and Li (1995) obtain a test under normality of ci and fuit g, based on the Lagrange multiplier principle ... obvious that Assumption FE.3 has the desired consequences of ensuring e‰ciency of fixed e¤ects and leading to simple computation of standard errors and test statistics Consider the demeaned equation...

Ngày tải lên: 06/07/2014, 08:20

... between xi1 , the levels of the explanatory variables, and the di¤erences Dxi2 ¼ xi2 À xi1 are often small Of course, whether the correlation is su‰cient to yield small enough standard errors depends ... example, Baltagi (1981); Cornwell, Schmidt, and Wyhowski (1992); and Kinal and Lahiri (1993) Example 11.5 (E¤ects of Smoking on Earnings): the e¤ects of cigarette smoking on earnings is logðwageit ... sources of asymptotic bias in the POLS estimator: correlation between xit and the unobserved e¤ect, ci , and a mea2 surement error bias term, Àbsr If xit and ci are positively correlated and b...

Ngày tải lên: 06/07/2014, 08:20

... values of yo , and decide on a sample size, N We then draw a random sample of size N from this distribution and use the sample to obtain an estimate of yo We draw a new random sample and compute ... more often than the nominal size of the test) See, for example, Davidson and MacKinnon (1993), Bera and McKenzie (1986), Orme (1990), and Chesher and Spady (1991) PN ~ ~ The Hessian form of the ... , Bo , Co , and , and can be estimated by using consistent estimators of Ao , Bo , and Co When we add assumption (12.53), then the special versions of the Wald and LM statistics and the QLR...

Ngày tải lên: 06/07/2014, 08:20

... true density of yi given x i , and not just one of many candidates It will be useful to let X H RK denote the possible values for x i and Y denote the possible values of yi ; X and Y are called ... of the dynamics—that is, that all lags of yt and z t have been properly accounted for in f ðyt j x t ; yo Þ and strict exogeneity of z t In most treatments of maximum likelihood estimation of ... T XX ^ A it ðy Þ; and i¼1 t¼1 ^ ^ s it ðy Þs it ðy Þ ð13:50Þ i¼1 t¼1 The validity of the second of these follows from a standard iterated expectations argument, and the last of these follows from...

Ngày tải lên: 06/07/2014, 08:20

... a linear demand and supply system for G attributes of a good or service (see Epple, 1987; Kahn and Lang, 1988; and Wooldridge, 1996) The demand and supply system is written as demandg ¼ h1g þ ... the struc- Generalized Method of Moments and Minimum Distance Estimation 433 tural demand and supply functions, we can use these as instruments in both the demand and supply equations Specifically, ... are linear in q i ; x i1 ; x i2 , and x i3 but nonlinear in the parameters Let u i1 be the G Â vector of attribute demand disturbances and u i2 the G Â vector of attribute supply disturbances...

Ngày tải lên: 06/07/2014, 08:20