Causal message ordering is a partial ordering of messages in a distributed computing environment. It places a restriction on communication between processes by requiring that if the transmission of messagemi to process pk necessarily preceded the transmission of message mj to the same process, then the delivery of these messages to that process must be ordered such that mi is delivered before m...

Abstract—QR decomposition and M-algorithm based near maximum likelihood detection (QRM-MLD) is a promising detection scheme for multiple-input multiple-output (MIMO) orthogonal frequency division multiplexing (OFDM). However, QRM-MLD requires still high computational complexity. Recently, we proposed a complexity reduced 2-step QRM-MLD for single-carrier (SC) block transmissions. The complexity...

We examine band-structure engineering in extremely tetragonal ferroelectric perovskites (ABO3) to make these materials suitable for photovoltaic applications. Using first-principles calculations, we study how B-site ordering, lattice strain, cation identity, and oxygen octahedral cage tilts affect the energies and the compositions of the valence and conduction bands. We find that extreme tetrag...

Article history: Received 1 July 2008 Received in revised form 17 October 2008 Accepted 2 November 2008 Available online 6 November 2008

In this paper we discuss the bounds of and relations among various kinds of intersection numbers of graphs. Especially, we address extremal graphs with respect to the established bounds. The uniqueness of the minimum-size intersection representations for some graphs is also studied. In the course of this work, we introduce a superclass of chordal graphs, defined in terms of a generalization of ...

In the given paper we investigate the problem of constructing a simulation model for the optimization of current stock of divisible productions in the warehouse. Criterion of optimization is minimum of average expenses for goods holding, ordering and losses from deficit and damage to the goods per time of season. The ExtendSim 8 package has been used as the means of simulation. The numerical ex...

The concept of residual lifetime has attracted considerable research interest in reliability theory. It is useful for evaluating the dynamic behavior of a system. In this paper, we study the extreme residual lives, that is, the minimum and maximum residual lives of the remaining components after the failure of the system. The system is assumed to have an arbitrary structure. We obtain signature...

‎we consider nonconvex vector optimization problems with variable ordering structures in banach spaces‎. ‎under certain boundedness and continuity properties we present necessary conditions for approximate solutions of these problems‎. ‎using a generic approach to subdifferentials we derive necessary conditions for approximate minimizers and approximately minimal solutions of vector optimizatio...

This study aims to deal with a more realistic combined problem of project scheduling and material ordering. The goal is to minimize the total material holding and ordering costs by determining the starting time of activities along with material ordering schedules subject to some constraints. The problem is first mathematically modelled. Then a hybrid simulated annealing and genetic algorithm is...