International Journal of Applied Operational Research

Assignment problem and its application in Nigerian institutions: Hungarian method approach

O. Solaja

Assignment model is a powerful operations research techniques that can be used to solve assignment or allocation problem. This study applies the assignment model to the course allocation problem in Nigeria tertiary institution in order to maximize lecturers’ effectiveness. A well-structured questionnaire was used to obtain data from lecturers and solved with Hungarian method. The study revealed that adoption of the assignment model in course allocation will help the institution to experience 13.20% increment in lecturers’ effectiveness in taking each topic in analysis for business decision. This will lead to increase in the quality of education students get. The study concluded that assignment model is a unique model that can be used to solve course allocation problems in tertiary institutions. The study then recommends that institutions should endeavor to adopt the assignment model in course allocation for optimal benefit and to improve the quality of education in the country.

Integrated technique for the optimization of healthcare facility problem

I. A. Osinuga

Access to basic health care services is one of the major issues in developing nations. The location of health care facilities is an important aspect in health care delivery. It is therefore necessary for health care services to be located optimally to serve the demands well. This study develops an integrated methodology in the field of healthcare location which minimizes the weighted average Euclidean distance between existing facilities and new facility in a way that demands will not have to travel a very long distance to access medical facilities. Geographic information systems (GIS) were used to store and handle the coordinates and weights of the existing facilities. While the Weber model and Weiszfeld’s algorithm was employed to determine the new healthcare location. The technique was applied to a case study in one of the local government areas in Nigeria. Our results show that the methodology can find a new facility to support demands in the study area. The proposed model can also be applied in studies of a similar nature as in location of library, medical drugs and equipment warehouse and support facility in emergency cases.

Interactive multiple objective programming in optimization of the fully fuzzy quadratic programming problems

H. A. Khalifa

In this paper, a quadratic programming (FFQP) problem is considered in which all of the cost coefficients, constraints coefficients, and right hand side of the constraints are characterized by L-R fuzzy numbers. Through this paper, the concept of α- level of fuzzy numbers for the objective function, and the order relations on the fuzzy numbers for the constraints are considered. To optimize the interval objective function, the order relations represented by decision maker's preference between intervals are defined by the right limit, the left limit, the center and the width of an interval. The maximization (minimization) problem with interval objective function is converted into a bi- objective problem and then the weighting method is applied for solving it and solves the new problem using the Kuhn- Tucker's necessary conditions. The advantages of the approach, referring to covert the fully fuzzy problem into the bi-objective problem, which is significant and being used in an interactive method for achieving the logical and applicable solutions. Finally, a numerical example is given to illustrate the utility, practically and the efficiency of the method.

A heuristic method to calculate the real internal rate of return (RIRR)

H. Jafari

The Internal Rate of Return (IRR) is used in economics as a popular method for project evaluation. Its major challenge, however, is to calculate all real rates. This paper presents an algorithm that can be used to calculate all return rates through introducing a heuristic approach based on several mathematical theorems. In order to better understand the different steps of the proposed algorithm, an overall description of the subject was first provided; it was then illustrated with more details through providing some examples. For the purpose of validation and accuracy of the results, the future value of the rates was also calculated at the end of each example. The results of the research showed that the new method had a relatively high efficiency to calculate all real rates. In addition, in the approach proposed in this paper, there is no need for the use of differentiation, and even recurring return rates are also identifiable.

Calculating the efficiency and productivity of decision making units with negative data

M. Khanmohammadi

Although non-negative data are fundamentally indispensable for determining the Malmquist productivity index (MPI), the observed values are sometimes negative in the real-world problems. In this paper, we reformulate the conventional Malmquist productivity index in data envelopment analysis (DEA) problem with negative data. So, first we want to introduce a non-radial efficiency model with negative data, then we use it in the Malmquist productivity index. At the end, we have tested the new proposed approach by the case study and applied to the productivity analysis of the 28 cement companies where are located in Iran’s Burs evolved between 2012 and 2013, because some of these companies have one negative output. In the analysis of the case study, we show that the index Malmquist (productivity) of companies is measured correctly. And because the index Malmquist calculations are done by computing efficiency, therefore it can be resulted that the efficiency of companies with negative data is measured correctly.