Introduction Conclusions References

The log-rank conjecture is one of the fundamental open problems in communication complexity. It speculates that the deterministic communication complexity of any two-party function is equal to the log of the rank of its associated matrix, up to polynomial factors. Despite much research, we still know very little about this conjecture. Recently, there has been renewed interest in this conjecture...

Here is a real gift to the field from David Johnson: After a thirteen year intermission, David is restarting his NP-completeness column. His column will now appear about twice yearly in ACM Transactions on Algorithms. Welcome back David, and thanks! And for those for whom a diet of two per year won’t do, meals past can be found at http://www.research.att.com/ ̃dsj/columns.html. As to the Complex...

We introduce a new concept in column generation for handling complex large scale optimization problems, called two-stage column generation, where columns for the compact and extensive formulation are simultaneously generated. The new framework is specifically conceived for tackling complex problems that cannot be efficiently solved by standard column generation and exploits the relationship bet...

Cloud-climate interactions are one of the greatest uncertainties in contemporary general circulation models (GCMs) (Cess et al. 1989, 1990), and the present study has focused on one aspect of this. Specifically, combined satellite and near-surface shortwave (SW) flux measurements have been used to test the impact of clouds on the SW radiation budget of two GCMs. Concentration is initially on SW...

Abstract: In this paper, an exergy analysis approach is proposed for optimal design of distillation column by using simulated annealing algorithm. First, the simulation of a distillation column was performed by using the shortcut results and irreversibility in each tray was obtained. The area beneath the exergy loss profile was used as Irreversibility Index in the whole column. Then, First Opti...

This research includes both experimental and CFD investigation in the hydrodynamic behavior of a new type of column tray introduced as “Concap” tray. The proposed column tray is used in contactor columns especially in stripping columns. The hydrodynamics of this Concap tray is investigated in a 1.2m in diameter column. Using air-water system, the experiments were performed for different liquid ...

the purpose of the present paper is to develop light beam method to measurement of interfacial area in a rectangular gas-liquid bubble column. total interfacial area can be determined in bubble column filled by transparent liquid by light transmission method. according to pervious researches, the fraction of parallel light is function of interfacial area and optical path length that these two p...