Social and Physical Planning for the Elimination of Urban Poverty

The provision of public facilities is also a traditional planning emphasis, dating back to the days when the planner was an ally of the reformers who were fighting for the establishment of these facilities. Out of this has come the belief that public facilities are crucial agencies in people\u27s lives, that up-to-date facilities and programs will encourage intensive use of them and that this in turn will help significantly in achieving the aims of guided mobility planning. Despite the intensity of the planner\u27s belief in neighborhood and public facility use, there is no evidence that these two planning concepts are as important to low income people as they are to planners. Consequently, it is fair to ask whether such concepts are as crucial to the elimination of urban poverty and deprivation as is signified by their appearance in some guided mobility plans. The answer to this question requires a brief discussion of the nature of contemporary urban poverty

Access regulation and the transition from copper to fiber networks in telecoms

In this paper we study the impact of different forms of access obligations on firms' incentives to migrate from the legacy copper network to ultra-fast broadband infrastructures. We analyze three different kinds of regulatory interventions: geographical regulation of access to copper networks-where access prices are differentiated depending on whether or not an alternative fiber network has been deployed; access obligations on fiber networks and its interplay with wholesale copper prices; and, finally, a mandatory switch-off of the legacy copper network-to foster the transition to the higher quality fiber networks. Trading-off the different static and dynamic goals, the paper provides guidelines and suggestions for policy makers' decision

Functional Aspects Of The Evolution Of Frog Tongues

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/137442/1/evo00952.pd

Efficient Computer Simulation of Polymer Conformation. I. Geometric Properties of the Hard-Sphere Model

A system of efficient computer programs has been developed for simulating the conformations of macromolecules. The conformation of an individual polymer is defined as a point in conformation space, whose mutually orthogonal axes represent the successive dihedral angles of the backbone chain. The statistical-mechanical average of any property is obtained as the usual configuration integral over this space. A Monte Carlo method for estimating averages is used because of the impossibility of direct numerical integration. Monte Carlo corresponds to the execution of a Markoffian random walk of a representative point through the conformation space. Unlike many previous Monte Carlo studies of polymers, which sample conformation space indiscriminately, importance sampling increases efficiency because selection of new polymers is biased to reflect their Boltzmann probabilities in the canonical ensemble, leading to reduction of sampling variance and hence to greater accuracy! in given computing time. The simulation is illustrated in detail. Overall running time is proportional to n^(5/4), where n is the chain length. Results are presented for a hard-sphere linear polymer of n atoms, with free dihedral rotation, with n = 20-298. The fraction of polymers accepted in the importance sampling scheme, fA, is fit to a Fisher-Sykes attrition relation, giving an effective attrition constant of zero. fA is itself an upper bound to the partition function, Q, relative to the unrestricted walk. The mean-squared end-to-end distance and radius of gyration exhibit the expected exponential dependence, but with exponent for the radius of gyration significantly greater than that of the end-to-end distance. The 90% confidence limits calculated for both exponents did not include either 6/5 or 4/3, the lattice and zero-order perturbation values, respectively. A self-correcting scheme for generating coordinates free of roundoff error is given in an Appendix

Structural optimization incorporating centrifugal and Coriolis effects

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76768/1/AIAA-1989-1310-955.pd

Computer Simulation of Polymer Conformation. II. Distribution Function for Polymers with Excluded Volume

Numerical distributions of end-to-end distances were generated by a Monte Carlo method for hard-sphere off-lattice polymers of length N = 20, 40, 60, 80, 98, and 298 atoms. Comparison by xz tests against five recently proposed theoretical distribution functions showed that for N = 80 and N = 98, the data could be described, with 95% confidence, by the equation f(r) = exp[ -(ar2 + br + c)], where a and b are fitted parameters and c is a normalization constant. For N = 298, limitations of sample size lead to lower confidence limits (about 80%), but good fit. The above equation, and not its gaussian counterpart exp( -cr^2), is probably the limiting distribution function. The function accurately predicts the 1st through 12th observed moments at all chain lengths