Location of a facility minimizing nuisance to or from a planar network

In this paper we investigate the location of a facility anywhere inside a planar network. Two equivalent problems are analyzed. In one problem it is assumed that the links of the network create a nuisance or hazard and the objective is to locate a facility where the total nuisance is minimized. An equivalent problem is locating an obnoxious facility where the total nuisance generated by the facility and inflicted on the links of the network is minimized. Exact and approximate solution methods for its solution are proposed and tested on a set of planar networks with up to 40,000 links yielding good results.     

Ethical flaws in training analysis.

With the spread of Freud's psychoanalytic movement, in numbers as well as in ideas, there came a time when what used to be informal "training," in the course of peripatetic or brief analyses with the master, was bureaucratized as a tripartite training system consisting of training analysis, didactic instruction, and analytic work under supervision. This was codified in the first official psychoanalytic institute, established in Berlin, that superseded the earlier tradition of Freud's Vienna. This development created a perennial tension between the goals of training and of treatment, with blurring of boundaries and creation of insurmountable ethical conflicts. The crux of the conflict is that the vested interests of the training analyst hamper the spirit of a good-enough treatment analysis: freedom of choice, suitable analysand-analyst fit, and more. This article is an analysis of these ethical conflicts and a plea for reform. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Unequivocal S(RN)1 route of vinyl halides with a multitude of competing pathways: reactivity and structure of the vinyl radical intermediate

Unambiguous examples of the vinylic S(RN)1 reaction initiated by a single-electron transfer from an electron-donor anion (Y(-)) to a suitable VyX substrate, and proceeding through a vinyl radical (Vy(*)()) intermediate, are described. Competition by alternative substitution routes is extensive, but through a systematic modification of the structure of the substrate, unequivocal examples of the vinylic S(RN)1 route are documented. The geometry of the Vy(*)() and kinetic parameters for H-abstraction and coupling with Y(-) are reported.     

An O(V 5/3 E 2/3) algorithm for the maximal flow problem

Summary A new algorithm for finding a maximal flow in a given network is presented. The algorithm runs in time O(V ^5/3 E ^2/3), where V and E are the number of the vertices and edges in the network. We use the notation A = 0(B) [A = Ω(B)] for A ≦ cB [A ≧ cB], and A = θ(B) for c ₁ B≦A ≦ c ₂ B where c, c ₁and c ₂are positive constants. (The same constants for all the occurrences of this notation)     

On the theoretical efficiency of various network flow algorithms

The time bounds of various algorithms for finding the maximal flow in networks are shown to be tight by constructing one parametrized family of network flow problems and showing that the algorithms achieve the corresponding bounds on inputs from this family.     

Some open problems in the theory of computation as questions about two-way deterministic pushdown automaton languages

We considered some of the important unsolved problems in the theory of computation concerning the relationship between deterministic and nondeterministic computations, and between tape and time bounded computations. For each such problem we find an equivalent problem concerning two-way deterministic pushdown automaton languages.This research was partially supported by ONR Grant N00014-67-A-0077-0021.     

The maximin gradual cover location problem

In this paper, we consider the multiple facility location problem with gradual cover. Gradual cover means that up to a certain distance from the facility a demand point is fully covered. Beyond another distance the demand point is not covered at all. Between these two distances the demand point is partially covered. When there are \(p\) facilities, the cover of each demand point can be calculated by a given formula. One objective in this setting is to find locations for \(p\) facilities that maximize the total cover. In this paper we consider another objective of maximizing the minimum cover of every demand point. This guarantees that every demand point is covered as much as possible and there are no demand points with low cover. The model is formulated and heuristic algorithms are proposed for its solution. We solved a real-life problem of locating cell phone towers in northern Orange County, California and demonstrated the solution approach on a set of 40 test problems.     

Maximal selection in tandem networks with symmetric hearing range

We consider an infinite tandem network in which every node is capable of hearing its neighbors up to a given distancen. At any moment of time every node may contain in the top of its queue a message destined to one of its neighbors. This network can be used as a model for a microwave or optic link with many users. For small and largen we investigate the maximal selection of nodes in the network, for which their transmissions are collision-free. For a large hearing range we show that the upper bound on the maximal selection, which is found herein, is asymptotically achievable. For small hearing ranges we show that a greedy selection is better but not asymptotically optimal. We also specify a sequence of upper bounds which converge to the maximal throughput.This research was done while J. M. Jaffe was on leave at the IBM Israel Scientific Center.