Given a simplicial complex K with weights on its simplices and a chain on it, the Optimal Homologous Chain Problem (OHCP) is to find a chain with minimal weight that is homologous (over Z) to the given chain. The OHCP is NP-complete, but if the boundary matrix of K is totally unimodular (TU), it becomes solvable in polynomial time when modeled as a linear program (LP). We define a condition on ...

We study the problem of designing the hyperlink structure between the web pages of a web site in order to maximize the revenue generated from the traffic on the web site. We show this problem is equivalent to the well-studied setting of infinite horizon discounted Markov Decision Processes (MDPs). Thus existing results from that literature imply the existence of polynomial-time algorithms for f...

Dead-end ultrafiltration (DEUF) is an alternative approach to tangential-flow hollow-fiber ultrafiltration that can be readily employed under field conditions to recover microbes from water. The hydraulics of DEUF and microbe recovery for a new DEUF method were investigated using 100-liter tap water samples. Pressure, flow rate, and temperature were investigated using four hollow-fiber ultrafil...

Along with the widely use in industries and lives, the dehumidification systems have consumed a large amount of energy. Fortunately, the application of liquid desiccant dehumidification system can greatly reduce the consumption of high-grade energy. To improve the advantages of liquid desiccant system compared with the conventional dehumidification system, one of the key measures is to increase...

The purpose of this paper is to extend the Rights Egalitarian solution (Herrero, Maschler & Villar, 1999) to the context of nontransferable utility sharing problems. Such an extension is not unique. Depending on the kind of properties we want to preserve we obtain two di¤erent generalizations. One is the "proportional solution", that corresponds to the Kalai-Smorodinsky solution for surplus sha...

Due to the wide range of design possibilities, simple manufactured, low maintenance and low cost, cross-flow heat exchangers are extensively used in the petroleum, petrochemical, air conditioning, food storage, and others industries. In this paper a mathematical model for cross-flow heat exchangers with complex flow arrangements for determining ε-NTU relations is presented. The model is based o...

This study aims to investigate the physico-chemical properties of some urban ponds in the ecological system of Lucknow which is called as the city of Nawabs in U.P. But owing to the unplanned development and urbanization, the ponds of this city are struggling for their existence. Inspite of the global alarm for restoration of the water bodies, the ponds in the city are facing neglectance. For t...

This project aims to synthesize laboratory-scale studies with a parallel large-eddy simulation sediment transport solver to gain a fundamental understanding of the mechanisms that govern clear-water scour around an abutment in a channel with a floodplain. In particular, we hope to answer how the interaction of the main channel flow with the floodplain affects the equilibrium scour depth. The st...