Computational Complexity

1 Department of Computer Engineering, Chonnam National university 300 Yongbong-dong, Buk-gu, Gwangju 500-757, Korea hthieu@hcmut.edu.vn, ykwon@chonnam.ac.kr 2 Dicision of Bionics and Bioinformatics, Chonbuk National University 664-14 St. #1 Dukjin-dong, ...

We propose in this article a unified approach to functional estimation problems based on possibly censored data. The general framework that we define allows, for instance, to handle density and hazard rate estimation based on randomly right-censored data, or regression. Given a collection of histograms, our estimation procedure consists in selecting the best histogram among that collection from the data,

The study of simple stochastic games (SSGs) was initiated by Condon for analyzing the computational power of randomized space-bounded alternating Turing machines. The game is played by two players, MAX and MIN, on a directed multigraph, and when the play terminates at a sink vertex s, MAX wins from MIN a payoff p(s)∈[0,1]. Condon proved that the problem SSG-VALUE—given a

Data exchange is the problem of taking data structured under a source schema and creating an instance of a target schema that reflects the source data as accurately as possible. In this paper, we address foundational and algorithmic issues related to the semantics of data exchange and to the query answering problem in the context of data exchange. These issues arise because, given a source instance, there may be many target instances that satisfy the constraints of the data exchange problem.

We provide two algorithms for computing the volume of the convex polytope Ω : = { x ∈ ℝ n + | Ax ≤ b }, for A , ∈ ℝ m × n , b ∈ ℝ n . The computational complexity of both algorithms is essentially described by n m , which makes them especially attractive for large n and relatively small m , when the other methods with O ( m n ) complexity fail. The methodology, which differs from previous existing methods, uses a Laplace transform technique that is well suited to the half-space representation of Ω.

This paper considers a design of signal constellations for trans-modulation (constellation rearrangement: CoRe) in a relay system with the multiple links in which the same signal is decoded-and-forwarded to the destination over N time slots, each assigned to the different relay node. Demonstrating that the minimal accumulated squared Euclidean distance (MASED) is not an ultimate design metric to minimize the bit error rate (BER), we choose the BER for the joint log-likelihood ratio (LLR) combining scheme as a design metric, so as to find bit-to-symbol mapping for the multiple relay links. To handle the prohibitive amount of computational complexity associated with an exhaustive search over enumeration of all possible mappings, which grows exponentially with the number of relay links, genetic algorithm is employed for searching for the sub-optimal bitto-symbol mappings in the multiple relay links. We show that a new type of CoRe design without the gray-mapping constraint is critical ...

This paper proposes a Hierarchical Evolutionary-Deterministic Algorithm (HEDA) for designing square grounding grids. This algorithm performs the design by means of a hierarchical coupling of a real coded evolutionary algorithm and the Hooke-Jeeves algorithm. The design of the grounding grid is here formalized as a min-max problem. The maximization part is the search of the most dangerous point for a given topological structure, the minimization part is the optimization of the topological parameter (compression ratio) of the grounding grid. The solution of the system of partial differential equations related to the spatial distribution of the current field is carried out by the Galerkin method. The program gives good results in terms of accuracy and computational complexity.

The progress in the field of computers in addition to improving our lives, is also helping to better understand the universe .
Understanding the logic of computing and information is changing the way we look at the universe
from the philosophical point of view and is helping us to better understand the physical laws that form the basis of cosmology .

We first advocate that the AUML (Agent Unified Modeling Language) notation, even in its new version, is not precise enough to adequately describe protocols. This problem was long identified by Harel and we propose to follow his solution: extend sequence diagrams with a ...