In a prospective survey, 200 cases of operated chronic dacryocystitis were divided into three groups according to the kind of operation, and the respective results are as follows: Group I includes 100 cases in whom the lacrimal bone was removed (8mm x 8mm) and a 6mm diameter catheter was used (as a duct between the lacrimal sac and nasal cavity). The recurrence rate within one year was 24 ...

The decision-making process on humanitarian logistics deals with variables related to the flow and quality of supplies, since the receipt of emergency relief items, its classification, stock, separation and delivery. Consequently, this decision-making process is crucial for seeking the best results in the allocation of scarce resources for storage and transportation in humanitarian operations, ...

We prove that combinatorial demand functions are characterized by two properties: continuity and the law of demand.

Operations research (OR) is concerned with scientifically deciding how to best design and operate people–machine systems, usually under conditions requiring the allocation of scarce resources. This publication, one of a series, is offered to supervisors, lead people, middle managers, and anyone who has responsibility for operations planning in manufacturing facilities or corporate planning over...

in this paper, some elementary operations on triangular fuzzynumbers (tfns) are defined. we also define some operations on triangularfuzzy matrices (tfms) such as trace and triangular fuzzy determinant(tfd). using elementary operations, some important properties of tfms arepresented. the concept of adjoints on tfm is discussed and some of theirproperties are. some special types of tfms (e.g. pu...

This paper deals with issues concerning the core as a solution concept for games in coalitional form as well as the use of these games in representing economies of a certain formal type. Side-payment games are imbedded in the more general class of no-side-payment games. It is shown that to a given side-payment game having an empty core one may associate two different no-side payment games with ...

We assume we have solved the problems (P) and (D), and that we have an optimal basis B ⊆ {1, 2, . . . , n}. Sensitivity analysis then refers to using to the basis B to solve a modified version (P’) and (D’) of the problems (P) and (D) from modified data A, b and c (whenever this information is useful). This is best done by example. Note that, if the optimal basic matrix AB remains unchanged, th...

Practitioners of Operations Research (OR) traditionally concentrate on mathematical and computational aspects of quantitative models, sometimes resulting in risky implementation or early model obsolescence. We propose an approach, inspired by system concepts and technology management, which includes softer influences, such as decision frequency, model life cycle and technological stage of manag...

This paper presents an approach to model-based diagnosis that rst compiles a rst-order system description to a propositional representation, and then solves the diagnostic problem as a linear programming instance. Relevance reasoning is employed to isolate parts of the system that are related to certain observation types and to economically instantiate the theory, while methods from operations ...