A FUZZY DECISION MAKING APPROACH IN EVALUATING FERRY SERVICE QUALITY

The service quality evaluation is undeniably important especially in highly competitive service related industry. However, service quality evaluation is not always straightforward as criteria in evaluation and customer perceptions toward services are intangible measures. This paper presents a fuzzy multi-criteria decision making approach for evaluating the service quality of ferry that transport customers between the mainland of Peninsular Malaysia and a tourist spot island. Service quality is a composite of various criteria, among them many criteria are intangible and difficult to measure. Fuzzy numbers and linguistic level based on fuzzy sets theory as a method to overcome vaguely judgment in evaluation. The crisp survey results were collected via a ten-service criteria questionnaire from eighty seven customers and computed using Best non-Fuzzy Performance and Degree of Similarity. Based on the concept of the defuzzification, the ranking of service performance is obtained. Degree of Similarity provides the level of satisfaction and its degrees for each criterion. The criterion of ‘service efficiency of ferry personnel’ was the first in the ranking. All the criteria received ‘good’ and ‘very good’ for the level of satisfaction. These evaluation results facilitate the ferry operator to upgrade its ferry services and eventually meet its customers’ needs.Service quality, fuzzy number, satisfaction level, defuzzification.

Modeling of Health Related Quality of Life Using an Integrated Fuzzy Inference System and Linear Regression

AbstractHealth Related Quality of Life (HRQL) is one of the increasing subjects used for assessing health condition among patients who suffer from specific diseases or illness. It has been assumed that multiple variables of HRQL would provide the one's overall health conditions. However, devising the extent of contribution of multiple variables towards overall health conditions is not straight forward as the arbitrary nature of HRQL variables. This paper aims to model the relationship between HRQL variables using an integrated model of fuzzy inference system and linear regression. An experiment was conducted to measure the strength of the relationship between variables and health indices among patients with chronic kidney diseases (CKD). To model this relationship, thirty outpatients with CKD were recruited from a government funded hospital in Peninsular Malaysia. Linguistic data were collected via guided interview and fed into the fuzzy inference system to yield HRQL indices. Multi-linear regressions were then undertaken to establish the relationship between variables and HRQL indices. The model shows that the variable of ‘unemployment’ was identified as the highest impact factor for patients with CKD. The employment of the integrated model, fuzzy inference system and multi-linear regressions were successfully identified the strength of the relationship between the multiple variables of HRQL and the health status

Ranking Causes of Road Accident Occurrence Using Extended Interval Type-2 Fuzzy TOPSIS

Over the past century there has been a dramatic increase in the number of road accidents in Malaysia. Hence, it is necessary to create a decision making method which can consider various preferences and criteria in order to identify the main causes of the accidents. This paper proposes an Interval Type-2 Fuzzy Technique for Order Preference by Similarity to Ideal Solution (IT2FTOPSIS) method which provides a comprehensive valuation from experts. This method is developed based on the aggregation of experts’ opinions on preferred causes of road accidents. The extended IT2FTOPSIS employs a linguistic scales of positive and negative Interval Type-2 Trapezoidal Fuzzy Number (IT2TrFN) and hybrid averaging approach (from an ambiguity and type-reduction methods) to formulate a collective decision environment. Three authorised personnel from three Malaysian Government agencies were interviewed where they were asked to rank the causes. The analysis shows that the linguistic scales of positive and negative Interval Type-2 Trapezoidal Fuzzy Number (IT2TrFN) and hybrid averaging approach are effective in measuring the uncertainties in the interviewees’ responses. Thus this paper concludes that the extended IT2FTOPSIS is more aligned with the users’ decisions compared to the earlier IT2FTOPSIS. Keywords: Multiple criteria decision-making; interval type-2 fuzzy set; IT2FTOPSIS; road accident

Fuzzy set conjoint model in describing students’ perceptions on computer algebra system learning environment

There are many ways of analysing effectiveness of learning especially in computer learning environment. However, not much attention has been given to analyse it from fuzzy theory perspective. Due to the fuzziness in perception toward learning, this paper presents an application of fuzzy set conjoint model in analyzing students’ perceptions on learning algebra and role of teacher in the presence of a computer algebra system (CAS). The study involves a survey which consists of eleven attributes in which six attributes were about learning algebra and another five attributes about role of teacher in a CAS learning environment. Data were collected from one hundred and sixty four students at a secondary school in Terengganu, Malaysia. Scores of perceptions were transformed into degree of similarity and level of agreement for attributes using fuzzy set conjoint model. It is found that attributes about learning indicate the highest degree of similarity at 0.77 with the level of ‘disagree’ while attributes about role of teacher measured at 0.81 degree of similarity with the level of ‘strongly agree’. These measurements implicate the successful of fuzzy approach to evaluate perceptions toward learning algebra in CAS environment. Keywords: fuzzy sets, conjoint model, perceptions, computer algebra system

Equilibrium linguistic computation method for fuzzy group decision making

This paper proposes an equilibrium computation method using linguistic variables based on the conflicting bifuzzy sets. The linguistic terms were defined and associated with the triangular fuzzy number as well as the labeling system in the early stages. Then, the negation operator was introduced and the bifuzzy approaches were employed to derive the aggregation equilibrium linguistic judgement for evaluation process

An overview of municipal solid wastes generation in Malaysia

Increasing population and tremendous urbanisation growth and other factors influence directly the municipal solid waste (MSW) generation in Malaysia. The huge quantity of MSW generation, particularly in Peninsular Malaysia, has increased from 16,200 tonnes per day in 2001 to 19,100 tonnes per day in 2005 or an average of 0.8 kg/capita/day. The amount increases yearly and seems to grow in parallel with the urban areas in many Asian countries which are estimated to produce approximately 8 million tonnes per day. Thus, this paper briefly discusses the scenario of MSW generation in Malaysia. It focuses on the trends of MSW generation, the composition of MSW, the contributing factors as well as the management problems occurring in Malaysia presently. In addition, some updated statistical figures related to the MSW and management aspects are provided to clarify the present situation and the government’s future planning. Recent development indicates that the Malaysian government has taken forward to deal with such problems in MSW management across the municipalities through closed dumping sites, upgrading existing conventional landfills to sanitary status, constructing new transfer stations and giving serious priority for an alternative disposal system in the near future. Moreover, the establishing a new national solid waste and public cleansing management corporation and enacted a new specific regulations for solid waste and public cleansing management which approved on September 2007 is also seen as a proactive step towards achieving the sustainability of MSW management as a long term solution

An Integrated Decision-Making Method Based on Neutrosophic Numbers for Investigating Factors of Coastal Erosion

The recent boom of various integrated decision-making methods has attracted many researchers to the field. The recent integrated Analytic Network Process and Decision Making Trial and Evaluation Laboratory (ANP–DEMATEL) methods were developed based on crisp numbers and fuzzy numbers. However, these numbers are incapable of dealing with the indeterminant and inconsistent information that exists in real-life problems

Perbandingan keputusan multi-atribut berasaskan beberapa teori set (Comparison of multi attributes decisions based on several set theories)

Dalam makalah ini dibincangkan analisis perbandingan keputusan multi-atribut yang diperoleh hasil daripada pendekatan penilaian menggunakan teori set ketara, set kabur, set kabur berintuisi dan set dwikabur konflik. Perbincangan tertumpu kepada analisis yang melibatkan penilaian secara dedua dalam teori set biasa, penilaian secara [0,1] dalam set kabur, penilaian secara ‘darjah keahlian’ dan ‘darjah bukan keahlian’ serta syarat 0 ≤ μA(x) + γA(x) ≤ 1 dalam set kabur berintuisi, dan penilaian secara ‘timbal balas’ (i.i., positif dan negatif) dalam set dwikabur konflik. Bagi tujuan ini, keempat-empat teori set dibincangkan secara ringkas dari aspek takrif, kesamaan dan perbezaan serta cara pendekatan yang digunakan untuk mendapat indeks hampiran relatif. Aplikasi pengiraan berangka secara bandingan menggunakan TOPSIS (Technique for Order Preference by Similarity to Ideal Solution) turut diberikan untuk semua pendekatan teori di atas. Keputusan pengiraan menunjukkan, perbezaan yang ketara pada nilai indeks hampiran relatif selain susunan keutamaan alternatif yang berbeza antara set ketara dengan teori set yang lain. Dapatan juga menunjukkan susunan keutamaan alternatif untuk tiga teori set kecuali set ketara adalah sama dan konsisten. Keputusan sebegini sekaligus memberi peluang dan ruang yang luas kepada penyelidik untuk mengkaji secara lebih mendalam pada masa hadapan. This paper discusses the comparison analyses for multi-attributes decision derived from crisp set, fuzzy set, intuitionistic fuzzy set and conflicting bifuzzy set. It focuses on the different evaluation approach using the binary system in crisp sets, the membership degree in [0,1] for fuzzy sets, the membership and non-membership degrees with condition 0 ≤ μA(x) + γA(x) ≤ 1 in intuitionistic fuzzy sets, and ‘equilibrium evaluation approach’ (i.e., positive and negative aspects) in conflicting bifuzzy sets. To meet these objectives, all the set theories are briefly discussed specifically the definitions, equalities, the differences as well as the different evaluation approaches to obtain the relative approximation index. A numerical example using Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) is also presented to clarify each of the above set theories. From the calculation results, it shows the significant differences of relative approximation index for each theory and different rating between the crisp set and other set theories. It is also found that all the set theories have recorded the same rating and consistent, except crisp sets. Thus, this situation offers wider opportunities to investigate more deeply and holistically for future research