SONFIDENTTAL It is not difficult to show that the survival probability is really asymptotically proportional to (1/n) exp [— en/(1 + Acs)] (n> &). (A16) BOMBS AIMED AT DIFFERENT POINTS a ee ee aeee Suppose that at each of the points (21, y1), .- ., (Zn) Yn), the bomb of Result 2 is aimed (with og = 72). This does not rule out the possibility that certain of these points may coincide; thus the discussion really includes the case of several bombs at each of several points and in particular the case of n bombs aimed at the center of the city. The expected level of casualties is clearly given by re v? c —A (-a)?+ (u-) I-sae i exp ( - 5 - 33)[1- 1+ Aad &xP ~~ 2 1 + Aah “| —A Saeko x [1- iwi iF EXP “> 4 wae 1+ ro3 (Al?) x [1 - T+ cro} PQ” 5°BY dhe? dé dv. —d a When this expression is expanded and integrated, there result 2" — 1 terms, of which the first n are of the form c V{i+ koi +o)[1+ Mos+1)] ex —4 2 zi LIFNos+o0%) + vi "1+ Xo +7) | the next l¢n(n — 1) of the form eC 1 1+Aoe Vf1 + X(o3 + 202)[1 + X(o8 + 273)] x ex —A k + rok + do?) (a? + 22) — 2r022,2, 2 (I+ do8)(1 + Ao} + 2A0%) (A19) + ditio | , and so on, the terms growing progressively more complicated. If, however, only two or three aiming points are considered, the resultant formulas are still practicable. It is interesting to remark that the terms in Eq. Al18 are what would result if the casualties from one bomb might be compounded with those of another by simple addition; the terms in Eq. A19 may be considered ‘‘ first-order corrections,”’ and so on. EVACUATION It would be well to close with a brief examination of the effect of evacuation efforts. Manycities have detailed plans about where they will transfer their populations and how long they will need to do so. From the point of view of this annex such reallocations of population constitute new cities for which a new bivariate analysis must be performed in order to arrive at casualty estimates. In this annex it is not a controlled evacuation, but rather a more or less unsupervised exodus, that is of interest. Certainly there is no overwhelmingly compelling evidence that this will not be the case, however good the intentions may be. ORO—R-17 (App B) 79 CONPB-ENTAGE PITAL IE TO NPs TTI SW ett ede ty be. Spe prin msess oat ce sree EETTDE ee PeM: War pitieWeere Papen —ppegren phepiphelaphatbtan rhmaddted peett geeetsire Peed aeeqepagtiresreeseieoat! peerage 5