A recursion category is locally connected if connected domains are jointly epimorphic. New proofs of the existence of non-complemented and recursively inseparable domains are given in a locally connected category. The use of local connectedness to produce categorical analogs of undecidable problems is new; the approach allows us to relax the hypotheses under which the results were originally pr...

this paper is focused on the tactical design of steel supply chain (ssc). a general mathematical model is proposed to integrate production and transportation planning in multi-commodity ssc. the main purpose is to prepare a countrywide production and distribution plan in an ssc with three layers consisting of iron ore mines as suppliers, steel companies as producers, and subsidiary steel compan...

Abstract It is the purpose of this article to introduce a linear approximation technique for solving a fractional chance constrained programming (CC) problem. For this purpose, a fuzzy goal programming model of the equivalent deterministic form of the fractional chance constrained programming is provided and then the process of defuzzification and linearization of the problem is started. A sam...

The multi-level programming problems are attractive for many researchers because of their application in several areas such as economic, traffic, finance, management, transportation, information technology, engineering and so on. It has been proven that even the general bi-level programming problem is an NP-hard problem, so the multi-level problems are practical and complicated problems therefo...

a real-time optimization (rto) strategy incorporating the fuzzy sets theory is developed, where the problem constraints obtained from process considerations are treated in fuzzy environment. furthermore, the objective function is penalized by a fuzzified form of the key process constraints. to enable using conventional optimization techniques, the resulting fuzzy optimization problem is then re...

Abstract We show that adjustable robust linear programs with affinely box data uncertainties under separable polynomial decision rules admit exact sums of squares (SOS) reformulations. These problems share the same optimal values and a one-to-one correspondence between solutions. A sum representation non-negativity non-convex over plays key role in reformulation. This reformulation allows us to...

the control problem and dynamic programming is a powerful tool in economics and management. we review the dynamic programming problem from its beginning up to its present stages. a problem which was involved in physics and mathematics in i 7” century led to a branch of mathematics called calculus of variation which was used in economic, and management at the end of the first quarter of the 20” ...

in this paper, the cost and income efficiency models have been considered with regard to the multiple objective programming structures. for finding the efficient points in purposed molp problem, some various methods like lexicography & the weighted sum can be used. so by introducing the molp problem the cost & income efficiencies will be achieved. in the present study, the molp problem ...

preventive maintenance scheduling is to perform a series of tasks that prevents or minimizes production breakdowns and improves the reliability. mathematical models have been developed to solve the preventive maintenance scheduling problem. there are several limitations in the prior work in this area of research. craft combinations are assumed to be given. the craft combination problem concerns...

This paper considers the problem of minimizing a convex, separable quadratic function subject to a knapsack constraint and a box constraint. An algorithm called NAPHEAP is developed for solving this problem. The algorithm solves the Karush-Kuhn-Tucker system using a starting guess to the optimal Lagrange multiplier and updating the guess monotonically in the direction of the solution. The start...