Duality relations are obtained for correlation functions of the q-state Potts model on any planar lattice or graph using a simple graphical analysis. For the two-point correlation we show that the correlation length is precisely the surface tension of the dual model, generalizing a result known to hold for the Ising model. For the three-point correlation an explicit expression is obtained relat...

We study links between approximation, exponential time computation and fixed parameter tractability. In particular, rather than focusing on one particular optimization problem, we tackle the question of finding sufficient conditions for a problem to admit “good” approximation algorithms in exponential time. In particular, we focus on the existence of “approximation schemata” (ratios 1 ± ǫ for a...

We study links between approximation, exponential time computation and fixed parameter tractability. In particular, rather than focusing on one particular optimization problem, we tackle the question of finding sufficient conditions for a problem to admit “good” approximation algorithms in exponential time. In particular, we focus on the existence of “approximation schemata” (ratios 1 ± ǫ for a...

A functional description of a communications satellite beacon receiver is presented. The system, designed primarily for LES-5/6, is capable of reliable unattended operation, and provides a frequency and time reference for fixed and highly mobile satellite communications terminals. Theoretical and experimental data are given, with particular emphasis on automatic acquisition and tracking of the ...

Variable power splitting ratio 2x2 MMI couplers using multimode waveguide holograms are analyzed. Theoretical analysis shows that variable splitting ratios can be obtained with surface relief holograms on MMI couplers with fixed dimensions. Devices with paired-imaging lengths are designed on a silicon-on-insulator (SOI) platform. Beam propagation simulations are used to verify a matrix theory a...

The concept of rapid delivery of multiple blood products to the bedside of a massively haemorrhaging patient seems to be a logical approach to the management of the massively bleeding patient. However, controversy exists in the use of fixed blood component ratios. Assessing the extent of the coagulopathy through point-of-care testing might provide patients with product administration as needed,...

in this paper, a concept of generalized weakly contraction mappings in partially ordered fuzzy metric spaces is introduced and  coincidence point  theorems on partially ordered fuzzy metric spaces are proved. also, as the corollary of these theorems, some common fixed point theorems on partially ordered fuzzy metric spaces are presented.

in this study it has been initiated to find out the credit strength and financial performance of cement industries in bangladesh through investigating the financial report for the period from 2007 to 2011. financial ratios are employed to measure the liquidity (working capital to total assets), profitability (retained earnings to total assets), efficiency (earnings before interest and taxes to ...

the importance as well as the difficulty of the problem of ranking fuzzy numbers is pointed out. here we consider approaches to the ranking of fuzzy numbers based upon the idea of associating with a fuzzy number a scalar value, its signal/noise ratios, where the signal and the noise are defined as the middle-point and the spread of each $gamma$-cut of a fuzzy number, respectively. we use the va...