Heribert Vollmer

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Thank you very much for reading introduction to circuit complexity a uniform approach. As you may know, people have search numerous times for their chosen books like this introduction to circuit complexity a uniform approach, but end up in malicious downloads. Rather than reading a good book with a cup of coffee in the afternoon, instead they are facing(More)
Let us imagine children playing with a box containing a large number of building blocks such as LEGOTM, fischertechnik, Polydron, or something similar. Each block belongs to a certain class (given by, e. g., color, shape, or size) and usually the number of different such classes is relatively small. It is amazing to see how involved the constructions are(More)
We explore the potentially "off-by-one" nature of the definitions of counting (#P versus #NP), difference (DP versus DNP), and unambiguous (UP versus UNP; FewP versus FewNP) classes, and make suggestions as to logical approaches in each case. We discuss the strangely differing representations that oracle and predicate models give for counting classes, and(More)
Schaefer proved in 1978 that the Boolean constraint satisfaction problem for a given constraint language is either in P or is NPcomplete, and identified all tractable cases. Schaefer’s dichotomy theorem actually shows that there are at most two constraint satisfaction problems, up to polynomial-time isomorphism (and these isomorphism types are distinct if(More)
We consider the following optimization problem for UMTS networks: For a specified teletraffic demand and possible base station locations, choose positions for base stations such that<ul><li>the construction costs are below a given limit, </li><li>as much teletraffic as possible is supplied, </li><li>the ongoing costs are minimal, and </li><li>the intra-cell(More)
We consider two optimization problems for cellular telephone networks, that arise in a recently discussed ITU proposal for a traffic load model. These problems address the positioning of base stations (on given possible locations) with the aim to maximize the number of supplied demand nodes and minimize the number of stations that have to be built. We show(More)
In a seminal paper from 1985, Sistla and Clarke showed that satisfiability for Linear Temporal Logic (LTL) is either NP-complete or PSPACE-complete, depending on the set of temporal operators used. If, in contrast, the set of propositional operators is restricted, the complexity may decrease. This paper undertakes a systematic study of satisfiability for(More)
We deene the counting classes #NC 1 , GapNC 1 , PNC 1 and C = NC 1. We prove that boolean circuits, algebraic circuits, programs over non-deterministic nite automata, and programs over constant integer matrices yield equivalent deenitions of the latter three classes. We investigate closure properties. We observe that #NC 1 #L, that PNC 1 L, and that C = NC(More)