Adibah Shuib

Rail passenger service delays: An overview

This paper draws an overview of rail passenger service disruptions which lead to service delays. Some findings on the train service delays in some parts of Asia and Western Europe are presented. The types and causes of service disruptions are analyzed across some rail network operators. The equivalent cost measures of delays done by past studies are also discussed. These costs are expressed in terms of monetary and time value. Finally, the benefits obtained from some improvement projects, are briefly addressed. In total, this review suggests that there is an urgent need to minimize service delays for passenger trains, which solution approaches may be obtained from a mathematical model.

Identifying the critical financial ratios for stocks evaluation: A fuzzy delphi approach

Stocks evaluation has always been an interesting and challenging problem for both researchers and practitioners. Generally, the evaluation can be made based on a set of financial ratios. Nevertheless, there are a variety of financial ratios that can be considered and if all ratios in the set are placed into the evaluation process, data collection would be more difficult and time consuming. Thus, the objective of this paper is to identify the most important financial ratios upon which to focus in order to evaluate the stock’s performance. For this purpose, a survey was carried out using an approach which is based on an expert judgement, namely the Fuzzy Delphi Method (FDM). The results of this study indicated that return on equity, return on assets, net profit margin, operating profit margin, earnings per share and debt to equity are the most important ratios.

Two-stage LP diet model for Malay households

For many low income households, eating well-balanced diet can be difficult to achieve because of the high prices of food. In addressing the issue, this paper will describe how minimum-cost healthy menus for a Malay household can be generated using a two-staged linear programming (LP) model. In Stage 1, LP sub-models were formulated to generate minimum cost daily diet plans which satisfy all nutrient requirements corresponding to the 11 respective pre-determined age-gender groups. Stage 2 involves optimizing the diet plans for the whole household to determine the minimum-cost daily menus. The daily menus, which consist of food for breakfast, lunch and dinner, were selected from a database of 121 Malay food and drinks. The costs of the food are configured from the price of food purchased from outside the house. The minimum-cost healthy diet menus generated using our LP model can also be used for estimating monthly food budgets and can easily be modified to cater to all income groups.

Preliminary time-based NFP model for heavy-tailed Islamic inheritance data

When the dual court system cannot totally and independently function on their own, serious problems affect the administration and distribution of Islamic inheritance causing increasing trends in the number of unclaimed inheritance, high degree of ignorance among Muslims of clear procedures to claim inheritance, and lengthy as well as costly claim processes. Investigation into the processes and procedures at institutions with the authority to distribute Islamic inheritance promotes the construction of a network flow programming model that clearly describes the precedence activities in the claim processes of Islamic inheritance. In particular, preliminary analysis of data characteristics contributes significantly toward defining a new method of estimating activity durations and specifying a time-window for effective range of the estimate.

Islamic inheritance claim processes — Non-normality data traits and best estimator choice

To confront and combat some of the issues in the administration and distribution of Islamic inheritance, Muslims have to look pass constitutional amendments and consider other alternatives as practical solutions to the problem of lengthy and costly claim procedures. Unveiling the uncertainties and confusion undergone by Muslims for so many years has provided the basis for our study to develop the network model and the mathematical model as solution approach to this problem. Careful analysis of variables using normality tests, descriptive statistics, normal and detrended plots as well as box-plots confirms the non-normality of variables, a finding upon which is built the assumption to use median absolute deviation as the best measure of variation to estimate activity durations of the model.

TAZ_OPT: A goal programming model for ambulance location and allocation

Ambulance is one of the emergency medical services (EMS) components. Quick ambulance response time for any emergencies is crucial in providing quality live-saving rescues. Strategic location and allocation of the ambulances is able to reduce the response time. This paper presents the Time-based Ambulance Zoning Optimization (TAZ_OPT) model, which determines the satellite locations of ambulances and the number of ambulances to be allocated at these stations. TAZ_OPT is a goal programming (GP) model. The model aims at maximizing the accessibility and the availability of ambulances.