scholarly journals Polynomial space hardness without disjunction property

2013 ◽  
Vol 467 ◽  
pp. 1-11 ◽  
Author(s):  
Simone Bova ◽  
Franco Montagna
Keyword(s):  
Polynomial Space ◽  
Disjunction Property

A Combinatorial Problem Which Is Complete in Polynomial Space

1976 ◽  
Vol 23 (4) ◽  
pp. 710-719 ◽  
Author(s):  
S. Even ◽  
R. E. Tarjan
Keyword(s):  
Combinatorial Problem ◽  
Polynomial Space

scholarly journals An Efficient Simulation of Polynomial-Space Turing Machines by P Systems with Active Membranes

2010 ◽  
pp. 461-478 ◽  
Author(s):  
Andrea Valsecchi ◽  
Antonio E. Porreca ◽  
Alberto Leporati ◽  
Giancarlo Mauri ◽  
Claudio Zandron
Keyword(s):  
P Systems ◽  
Polynomial Space ◽  
Turing Machines ◽  
Efficient Simulation ◽  
Active Membranes

Characterization and construction of helical polynomial space curves

2004 ◽  
Vol 162 (2) ◽  
pp. 365-392 ◽  
Author(s):  
Rida T. Farouki ◽  
Chang Yong Han ◽  
Carla Manni ◽  
Alessandra Sestini
Keyword(s):  
Polynomial Space ◽  
Space Curves

scholarly journals Probabilistic Reasoning Across the Causal Hierarchy

2020 ◽  
Vol 34 (06) ◽  
pp. 10170-10177 ◽  
Author(s):  
Duligur Ibeling ◽  
Thomas Icard
Keyword(s):  
Bayesian Inference ◽  
Conditional Independence ◽  
Probabilistic Reasoning ◽  
Causal Models ◽  
Causal Effects ◽  
Polynomial Space ◽  
The Third ◽  
Probabilistic Programs

We propose a formalization of the three-tier causal hierarchy of association, intervention, and counterfactuals as a series of probabilistic logical languages. Our languages are of strictly increasing expressivity, the first capable of expressing quantitative probabilistic reasoning—including conditional independence and Bayesian inference—the second encoding do-calculus reasoning for causal effects, and the third capturing a fully expressive do-calculus for arbitrary counterfactual queries. We give a corresponding series of finitary axiomatizations complete over both structural causal models and probabilistic programs, and show that satisfiability and validity for each language are decidable in polynomial space.

scholarly journals Minimal unlinking pathways as geodesics in knot polynomial space

2020 ◽  
Vol 3 (1) ◽  
Author(s):  
Xin Liu ◽  
Renzo L. Ricca ◽  
Xin-Fei Li
Keyword(s):  
Polynomial Space ◽  
Knot Polynomial

APPROXIMATING ASYMMETRIC TSP IN EXPONENTIAL TIME

2014 ◽  
Vol 25 (01) ◽  
pp. 89-99 ◽  
Author(s):  
ALEXANDER GOLOVNEV
Keyword(s):  
Traveling Salesman Problem ◽  
Directed Graph ◽  
Short Note ◽  
Simple Algorithm ◽  
Computable Function ◽  
Traveling Salesman ◽  
Polynomial Space ◽  
Exponential Time ◽  
Running Time ◽  
Polynomial Factor

Let G be a complete directed graph with n vertices and integer edge weights in range [0,M]. It is well known that an optimal Traveling Salesman Problem (TSP) in G can be solved in 2n time and space (all bounds are given within a polynomial factor of the input length, i.e., poly(n, log M)) and this is still the fastest known algorithm. If we allow a polynomial space only, then the best known algorithm has running time 4nnlog n. For TSP with bounded weights there is an algorithm with 1.657n · M running time. It is a big challenge to develop an algorithm with 2n time and polynomial space. Also, it is well-known that TSP cannot be approximated within any polynomial time computable function unless P=NP. In this short note we propose a very simple algorithm that, for any 0 < ε < 1, finds (1+ε)-approximation to asymmetric TSP in 2nε−1 time and ε−1 · poly(n, log M) space. Thereby, for any fixed ε, the algorithm needs 2n steps and polynomial space to compute (1 + ε)-approximation.

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