the importance of energy crisis and global warming necessitates presenting strategies in order to decrease the amount of emissions as well as fuel consumption in large and complex industries such as refineries and petrochemical industries. generally, refinery steam networks are regarded as units which consume fuel enormously. in this paper, the steam network of tehran oil refinery is considered...

the star-mesh transformation allows the reduction of nodes in an electrical circuit. the gauss elimination method allows the reduction of unknowns in a system of linear equations . triangular decomposition can be used to find the inverse of a matrix. in this paper the coherence between these methods are discussed. it is shown that the gauss elimination method gives the same formula for star-mes...

in this paper, we study the problem of integrated capacitated hub location problem and seat inventory control considering concept and techniques of revenue management. we consider an airline company maximizes its revenue by utilizing the best network topology and providing proper booking limits for all itineraries and fare classes. the transportation system arises in the form of a star/star net...

We resolve an open question by determining matching (asymptotic) upper and lower bounds on the state complexity of the operation that sends a language L to (

Green Marketing is becoming a buzz for the society nowadays and people start shifting their demands towards a product which is related towards environmental safeguard. Nowadays companies from different industries sectors are showing their keen interest and taking various initiatives towards green marking. Electronic products having eco safeguard and are less detrimental to the environment are l...

current study aims to prioritize four-star hotels through atwo-step procedure: firstly, classifying service quality dimensions (sqds)based on importance-performance analysis and secondly prioritizinghotels based on classified sqds analysing the results. to reach that aim,the customers of three 4-star hotels were considered and asked to statethe quality of the service they expected to receive pr...

the interacting two winds model and a spherical density distribution function are introduced to study the dynamical and ionization structure of the planetary nebula ic 418. a fast wind with a mechanical luminousity  2/34×1034erg.s-1 of interacts with a super wind with a mass-loss rate of  2×10-5m(°)yr-1 and  a velocity of 10 , and produces a dense and luminous medium.   in this model, the expan...

Let $(A)$ be a complex $(ntimes n)$ matrix and assume that the numerical range of $(A)$ lies in the set of a sector of half angle $(alpha)$ denoted by $(S_{alpha})$. We prove the numerical ranges of the conjugate, inverse and Schur complement of any order of $(A)$ are in the same $(S_{alpha})$.The eigenvalues of some kinds of matrix product and numerical ranges of hadmard product, star-congruen...