A lower bound on the local time complexity of universal constructions

1998 ◽  
Author(s):  
Prasad Jayanti
Keyword(s):  
Lower Bound ◽  
Local Time ◽  
Time Complexity ◽  
Universal Constructions

Lower bound on the time complexity of local adiabatic evolution

2006 ◽  
Vol 74 (5) ◽  
Author(s):  
Zhenghao Chen ◽  
Pang Wei Koh ◽  
Yan Zhao
Keyword(s):  
Lower Bound ◽  
Time Complexity ◽  
Adiabatic Evolution

SIMULATIONS BY TIME-BOUNDED COUNTER MACHINES

2011 ◽  
Vol 22 (02) ◽  
pp. 395-409 ◽  
Author(s):  
HOLGER PETERSEN
Keyword(s):  
Lower Bound ◽  
Real Time ◽  
Polynomial Time ◽  
Time Complexity ◽  
Linear Time ◽  
Fixed Number ◽  
Exponential Time ◽  
New Family ◽  
Counter Machines ◽  
Time Bounds

We investigate the efficiency of simulations of storages by several counters. A simulation of a pushdown store is described which is optimal in the sense that reducing the number of counters of a simulator leads to an increase in time complexity. The lower bound also establishes a tight counter hierarchy in exponential time. Then we turn to simulations of a set of counters by a different number of counters. We improve and generalize a known simulation in polynomial time. Greibach has shown that adding s + 1 counters increases the power of machines working in time ns. Using a new family of languages we show here a tight hierarchy result for machines with the same polynomial time-bound. We also prove hierarchies for machines with a fixed number of counters and with growing polynomial time-bounds. For machines with one counter and an additional "store zero" instruction we establish the equivalence of real-time and linear time. If at least two counters are available, the classes of languages accepted in real-time and linear time can be separated.

An improved lower bound for the time complexity of mutual exclusion

2002 ◽  
Vol 15 (4) ◽  
pp. 221-253 ◽  
Author(s):  
James H. Anderson ◽  
Yong-Jik Kim
Keyword(s):  
Lower Bound ◽  
Time Complexity ◽  
Mutual Exclusion

SCHEDULING OF THE DAG ASSOCIATED WITH PIPELINE INVERSION OF TRIANGULAR MATRICES

1996 ◽  
Vol 06 (01) ◽  
pp. 13-26 ◽  
Author(s):  
CLEMENTIN TAYOU DJAMEGNI ◽  
MAURICE TCHUENTE
Keyword(s):  
Lower Bound ◽  
Linear Systems ◽  
Time Complexity ◽  
Canonical Basis ◽  
Triangular Matrix ◽  
Dependence Graph ◽  
Triangular Matrices

We are interested in methods which compute the inverse of a triangular matrix A of order n by solving the n linear systems Ax=ei, i=1,…, n, where ei is the i-th element of the canonical basis of Rn. More precisely, we consider the dependence graph associated with algorithms where the entries of matrix A are read only once and used in pipeline for the solution of these systems. We exhibit a new scheduling which induces an algorithm with time complexity T*=2n−1. The number n2/8+O(n) of processors required by this scheduling improves the best previously known bound n2/6+O(n), and is quite close to the lower bound n2/8.5+O(n).

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