Прегледај по Аутор "Tanackov, Ilija"
Сада се приказује 1 - 16 од 16
Резултати по страници
Опције сортирања
- СтавкаA New Methodology for Improving Service Quality Measurement: Delphi-FUCOM-SERVQUAL Model(MDPI, 2018) Prentkovskis, Olegas; Erceg, Živko; Stević, Željko; Tanackov, Ilija; Vasiljević, Marko; Gavranović, MladenThe daily requirements and needs imposed on the executors of logistics services imply the need for a higher level of quality. In this, the proper execution of all sustainability processes and activities plays an important role. In this paper, a new methodology for improving the measurement of the quality of the service consisting of three phases has been developed. The first phase is the application of the Delphi method to determine the quality dimension ranking. After that, in the second phase, using the FUCOM (full consistency method), we determined the weight coefficients of the quality dimensions. The third phase represents determining the level of quality using the SERVQUAL (service quality) model, or the difference between the established gaps. The new methodology considers the assessment of the quality dimensions of a large number of participants (customers), on the one hand, and experts’ assessments on the other hand. The methodology was verified through the research carried out in an express post company. After processing and analyzing the collected data, the Cronbach alpha coefficient for each dimension of the SERVQUAL model for determining the reliability of the response was calculated. To determine the validity of the results and the developed methodology, an extensive statistical analysis (ANOVA, Duncan, Signum, and chi square tests) was carried out. The integration of certain methods and models into the new methodology has demonstrated greater objectivity and more precise results in determining the level of quality of sustainability processes and activities.
- СтавкаA Novel Hybrid Interval Rough SWARA–Interval Rough ARAS Model for Evaluation Strategies of Cleaner Production(MDPI, 2022) Tanackov, Ilija; Badi, Ibrahim; Stević, Željko; Pamučar, Dragan; Kazimieras Zavadskas, Edmundas; Bausys, RomualdasCleaner production is certainly a challenge of our everyday life, and a lot of effort and energy is required to achieve it. This paper has created a model of five strategies for cleaner production in Libyan industry, which have been evaluated on the basis of eight criteria. In order to determine the significance of the criteria, a novel interval rough SWARA (step-wise weight assessment ratio analysis) method has been developed, which takes into account the preferences of decision-makers (DMs) by applying interval rough numbers. A novel interval rough ARAS (additive ratio assessment) method has been developed for the evaluation and selection of the most favorable strategy for cleaner production. The integration of the developed methods has yielded results showing that the first strategy, launching awareness-raising campaigns to publicize these policies, represents the most realistic and best current solution to achieve cleaner production in Libyan industry. A comparative analysis with some existing interval rough methodologies has been presented to verify the superiority of the proposed model. In addition, in a sensitivity analysis, the weight of the most significant criterion has been changed.
- СтавкаA NOVEL IMF SWARA FDWGA PESTEL ANALYSIS FOR ASSESSMENT OF HEALTHCARE SYSTEM(2022) Vojinović, Nikolina; Stević, Željko; Tanackov, IlijaDecision-making represents a very popular field with many developed approaches. However, still exists the need for the creation of novel integrated models such as well is the case in this paper. The novel integrated Improved Fuzzy Stepwise Weight Assessment Ratio Analysis (IMF SWARA) method, Fuzzy Dombi weighted geometric averaging (FDWGA) operator and PESTEL (P-Political, E-Economic, S-Social, T-Technological, E-Environmental, L-Legal) model has been developed. Five decision makers (DMs) have evaluated six main elements of the PESTEL analysis and 30 elements more (five for each group). In total, we have created 35 models based on the developed model. Results of PESTEL analysis based on IMF SWARA method and FDWGA shows that legal and economic factors represent the most significant parameters, while last placed belong environmental group. Also, the usefulness of the developed integrated model has been demonstrated.
- СтавкаA Novel Integrated SWARA-MARCOS Model for Inventory Classification(Iran University of Science and Technology, 2021) Miškić, Smiljka; Stević, Željko; Tanackov, IlijaIn the field of logistics, there is a daily need for decision making, i.e. the need to solve business problems by selecting an appropriate solution. During the implementation of decision-making processes, it is necessary to find an optimal solution that will best meet the needs of companies. The selection of an optimal solution is crucial for the profitability, cost-effectiveness and long-term development of companies. The decision-making process in logistics is facilitated by applying various tools such as multi-criteria decision-making methods. In this paper, an integrated SWARA (Step-wise Weight Assessment Ratio Analysis) – MARCOS (Measurement Alternatives and Ranking according to Compromise Solution) model was developed and applied in order to classify products. Fifty alternatives, i.e. products were evaluated based on three criteria. The first criterion is the quantity of purchased products, the second criterion is the unit price of products and the third criterion is the annual value of purchase. The SWARA method was applied to determine the significance of the criteria, while the classification of products was performed using the MARCOS method. According to the results of the originally created MCDM model, the products were grouped into three categories A, B, and C. Then, a sensitivity analysis was performed using a model involving the integration of SWARA method and ABC analysis. Using this model, the classification of products into three groups was performed on the basis of the aforementioned criteria, and then a comparative analysis was conducted
- СтавкаAmmonia-risk distribution by logistic subsystems and type of consequence(Elsevier, 2020) Sremac, Siniša; Ziramov, Nikola; Tanackov, Ilija; Stević, Željko; Ristić, BojanaDetailed quantitative analysis of results, influence of position within logistic systems and consequence of dangerous goods ammonia has been done based on a sample of 1165 workers or third persons involved in 295 accidents. Results of accidents for those involved have been classified as unhospitalized, hospitalized survived, hospitalized deceased and killed. From the logistic point of view accidents with ammonia are located in production, storage, reloading, transport and use subsystems. ammonia’s consequences are systematized in the following manner: Respiratory–Toxic (RT), Cold Injury (CI), Fire and Burns (FB), and mechanical consequences after explosions (EX). Distribution laws for unhospitalized, hospitalized, deceased and killed have been determined. The highest average number of persons involved in an accident has been determined in the production subsystem. Cold Injury by ammonia in 47.5% of accidents includes 65.23% of persons involved in accident, but the most invasive consequence of ammonia is RT. Significantly critical fatal outcomes of accidents has been found for Respiratory–Toxic consequence of ammonia in the reloading subsystem, with extremely high average value of 0.4193 killed per accident. Based on obtained results of research certain procedures are proposed to reduce the risk of serious consequences of ammonia’s dangerous influence
- СтавкаAN INTEGRATED DECISION-MAKING MODEL FOR EFFICIENCY ANALYSIS OF THE FORKLIFTS IN WAREHOUSING SYSTEMS(University of Niš, Serbia, 2021) Mahmutagić, Eldina; Stević, Željko; Nunić, Zdravko; Chatterjee, Prasenjit; Tanackov, IlijaIn the logistics world, special attention should be given to warehousing systems, cost rationalization, and improvement of all the factors that affect efficiency and contribute to smooth functioning of logistics subsystems. In real time industrial practice, the issue of evaluating and selecting the most appropriate forklift involves a complex decision-making problem that should be formulated through an efficient analytical model. The forklifts efficiency plays a very important role in the company. The forklifts are being used on a daily basis and no logistical processes could be done without them. Therefore, it has been decided to determine their efficiency, which will contribute to the optimization of the process in this logistics subsystem. This study puts forward an integrated forklift selection model using Data Envelopment Analysis (DEA), Full Consistency Method (FUCOM) and Measurement Alternatives and Ranking According to the Compromise Solution (MARCOS) methods. Five input parameters (regular servicing costs, fuel costs, exceptional servicing costs, total number of all minor accidents and damage caused by forklifts) and one output parameter (number of operating hours) were first identified to assess efficiency of eight forklifts in a warehousing system of the Natron-Hayat company using the DEA model. This step allows sorting of efficient forklifts which are subsequently evaluated and ranked using FUCOM and MARCOS methods. A sensitivity analysis is also performed in order to check reliability and accuracy of the results. The findings of this research clearly show that the proposed decision-making model can significantly contribute to all spheres of business applications
- СтавкаAN INTEGRATED FUZZY AHP AND TOPSIS MODEL FOR SUPPLIER EVALUATION(University of Belgrade, Serbia, 2016) Stević, Željko; Tanackov, Ilija; Vasiljević, Marko; Novarlić, Boris; Stojić, GordanIn today’s modern supply chains, the adequate suppliers’ choice has strategic meaning for entire companies’ business. The aim of this paper is to evaluate different suppliers using the integrated model that recognizes a combination of fuzzy AHP (Analytical Hierarchy Process) and the TOPSIS method. Based on six criteria, the expert team was formed to compare them, so determination of their significance is being done with fuzzy AHP method. Expert team also compares suppliers according to each criteria and on the base of triangular fuzzy numbers. Based on their inputs, TOPSIS method is used to estimate potential solutions. Suggested model accomplishes certain advantages in comparison with previously used traditional models which were used to make decisions about evaluation and choice of supplier.
- СтавкаANFIS MODEL FOR DETERMININ G THE ECONOMIC ORDER QUANTITY(2018) Sremac, Siniša; Tanackov, Ilija; Kopić, Miloš; Radović, DunjaThe determination of the economic order quantity is important for the rational realization of the logistics process of transport, manipulation and storage in the supply chain. In this paper an expert model for the determination of the economic order quantity has been developed. The model has been developed using the hybrid method of artificial intelligence Adaptive neuro-fuzzy inference systems - ANFIS. It has been used for modeling a complex logistics process in which it is difficult to determine the interdependence of the presented variables applying classical methods. The hybrid method has been applied to take advantages of the individual methods of artificial intelligence: fuzzy logic and neural networks. Experience of an experts and information on the operations of the company for a certain group of items have been used to form the model. Analysis of the validity of the model results was performed on the basis of the average relative error and it has showed that the model imitates the work of the expert in the observed company with great accuracy. Sensitivity analysis has been applied which indicates that the model gives valid results. The proposed model is flexible and can be applied to various types of goods in supply chain management
- СтавкаASSESSING THE PERFORMANCE OF SUB-SAHARAN AFRICAN (SSA) RAILWAYS BASED ON AN INTEGRATED ENTROPY-MARCOS APPROACH(2021) Bouraima, Mouhamed Bayane; Stević, Željko; Tanackov, Ilija; Qiu, YanjunIn this study, the performance of Sub-Saharan African railways systems (SSA) is assessed by using an integrated Entropy-MARCOS (Measurement Alternatives and Ranking according to COmpromise Solution) - based methodology. In the first phase, the Entropy method is employed to determine the weights of each sub-criterion of the decision model. This process identifies six main criteria, i.e., safety, security, internal business aspect, intermodal aspect, innovation, and learning aspect, and customer satisfaction which are further supplemented by 13 sub-criteria. In the second phase, the MARCOS method is used to rank the countries based on their railway performance assessment. Based on the results from the proposed method, a sensitivity analysis was carried out through a comparative analysis with seven other multicriteria decision-making (MCDM) methods. The results of the study indicate that the most weighted sub-criterion is the labor productivity (internal business perspective criteria) followed by the terrorist incidence (security criteria) and the number of employees going through training/exposure sessions (innovation and learning perspective criteria). Moreover, it was revealed that Kenya is the best alternative in terms of its railway performance followed by Ethiopia, Cameroon, Nigeria, and Ghana. Based on the findings from this study, decision-makers can be assisted during the operative, designing, and planning investigations of the railway system through the consideration of these parameters as insert indicators. Also, the findings can help as a benchmark for the performance analysis of other railway systems in other African countries
- СтавкаCalculation of the value of the critical line using multiple zeta functions(AIMS Press, 2023) Tanackov, Ilija; Stević, ŽeljkoNewton’s identities of an infinite polynomial with complex conjugate roots n−( +it) and n−( it) are multiple zeta functions for n 1, ), R and t R. All Newton’s identities can be represented by Macdonald determinants. In a special case of the Riemann hypothesis, the multiple zeta function of the first order is equal to zero, ( +it)+ ( it)=0. The special case includes all non trivial zeros. The value of the last, infinite multiple zeta function, in the special case, changes the structure of the determinant that can be calculated. The result is the reciprocal of the factorial value (n!) 1. The general value of the infinite multiple zeta function is calculated based on Vieta’s rules and is equal to (n!) 2 . The identity based on the relation of the special case and the general case (n!) 1=(n!) 2 is reduced to the equation 1= 2 . The value of the critical line for all non trivial zeros is singular, =½.
- СтавкаDevelopment of Modified SERVQUAL–MCDM Model for Quality Determination in Reverse Logistics(MDPI, 2021) Stević, Željko; Tanackov, Ilija; Puška, Adis; Jovanov, Goran; Vasiljević, Jovica; Lojaničić, DarkoTo run a business successfully, quality determination and customer relations are very important factors. Therefore, it is necessary to measure quality and identify critical points of business. In this paper, an original integrated model for measuring the service quality of reverse logistics (RL) was developed for the company Komunalac Tesli´c, which was used as an example. The Delphi and Full Consistency Method (FUCOM) was applied to determine the significance of the quality dimensions, while a modified SERVQUAL (SQ) model was used to measure the service quality of the logistics. An original SQ questionnaire was formed with a total of 21 statements that were arranged in five standard dimensions. Examining the reliability of the questionnaire for quality dimensions using the Cronbach Alpha coefficient, it was found that the measurement scales for dimensions are appropriate in terms of user expectations, while in terms of quality perception there is no measurement scale for the empathy dimension. An extensive statistical analysis was then performed to verify the results. A Signum test was applied to identify the relationship between the responses in terms of expectations and perceptions, i.e., to examine their differences. The findings obtained by this research show that the expectations were higher than the perceived quality of the services and that there was a significant statistical difference for 12 of the SQ statements. For two statements, there was a significant statistical difference in favor of perceived quality compared to expectations. Based on the results obtained, the company must improve its services in order for service quality to be at a satisfactory level.
- СтавкаIMPACT OF THE NUMBER OF VEHICLES ON TRAFFIC SAFETY: MULTIPHASE MODELING(University of Niš, 2022) Damjanović, Milanko; Stević, Željko; Stanimirović, Dragan; Tanackov, Ilija; Marinković, DraganTraffic safety is one of the key issues nowadays, given the fact that a large number of people lose their lives in traffic accidents every day. There are various influential factors in the occurrence of traffic accidents, the number of vehicles being one of them. This paper assesses the traffic safety in Montenegro in the period 1998-2020 by applying the multiphase modeling with a purpose to obtain comparative results which enable implementation of adequate strategies. A total of six scenarios were formed with two inputs and two outputs in a DEA (Data Envelopment Analysis) model, with the number of registered vehicles per year being an input in all scenarios. In addition, as inputs, the scenarios included AADT (Annual Average Daily Traffic), passengers in road transport, passenger-km by road transport, goods transported by road, tone-km by road, and passengers in local transport. The number of traffic accidents with casualties, the number of traffic accidents with material damage, the number of fatal cases and the number of injured persons, depending on a scenario, were observed as outputs. After the DEA model, IMF SWARA (Improved Fuzzy Stepwise Weight Assessment Ratio Analysis) was applied to determine the weights of inputs and outputs, while the final state of traffic safety by years was determined using the MARCOS (Measurement of alternatives and ranking according to COmpromise solution) method.
- СтавкаModel for Risk Calculation and Reliability Comparison of Level Crossings(MDPI, 2021) Ercegovac, Pamela; Stojić, Gordan; Kopić, Miloš; Stević, Željko; Sinani, Feta; Tanackov, IlijaThere is not a single country in the world that is so rich that it can remove all level crossings or provide their denivelation in order to absolutely avoid the possibility of accidents at the intersections of railways and road traffic. In the Republic of Serbia alone, the largest number of accidents occur at passive crossings, which make up three-quarters of the total number of crossings. Therefore, it is necessary to constantly find solutions to the problem of priorities when choosing level crossings where it is necessary to raise the level of security, primarily by analyzing the risk and reliability at all level crossings. This paper presents a model that enables this. The calculation of the maximal risk of a level crossing is achieved under the conditions of generating the maximum entropy in the virtual operating mode. The basis of the model is a heterogeneous queuing system. Maximum entropy is based on the mandatory application of an exponential distribution. The system is Markovian and is solved by a standard analytical concept. The basic input parameters for the calculation of the maximal risk are the geometric characteristics of the level crossing and the intensities and structure of the flows of road and railway vehicles. The real risk is based on statistical records of accidents and flow intensities. The exact reliability of the level crossing is calculated from the ratio of real and maximal risk, which enables their further comparison in order to raise the level of safety, and that is the basic idea of this paper.
- СтавкаNatural Test for Random Numbers Generator Based on Exponential Distribution(MDPI, 2019) Tanackov, Ilija; Sinani, Feta; Stanković, Miomir; Bogdanović, Vuk; Stević, Željko; Vidić, Mladen; Mihaljev-Martinov, JelenaWe will prove that when uniformly distributed random numbers are sorted by value, their successive di erences are a exponentially distributed random variable Ex( ). For a set of n random numbers, the parameters of mathematical expectation and standard deviation is = n1. The theorem was verified on four series of 200 sets of 101 random numbers each. The first series was obtained on the basis of decimals of the constant e = 2.718281 : : : , the second on the decimals of the constant = 3.141592 : : : , the third on a Pseudo Random Number generated from Excel function RAND, and the fourth series of True Random Number generated from atmospheric noise. The obtained results confirm the application of the derived theorem in practice.
- СтавкаSustainable development solutions of public transportation:An integrated IMF SWARA and Fuzzy Bonferroni operator(Elsevier, 2023) Moslem, Sarbast; Stević, Željko; Tanackov, Ilija; Pilla, FrancescoDeveloping the quality of public transport has an efficient impact to attract more users to switch modes from private vehicles to public transport, which has a tremendous capability in reducing the traffic congestion, noise and CO2 emissions the urban areas. For this reason, policy makers and scholars aim to enhance the supply quality of public transport system, where involving citizens along with experts and decision makers in the decision process will reflect the existed and future demand to provide more sustainable solutions which provide efficient solutions to achieve positive impacts on the local environment. This study intends to determine the preference of decision-makers and operators for the importance of the supply quality elements of urban bus transport services in Mersin city, Turkey. For this aim, decision makers and experts are involved in the evaluation process to provide feedback on public transport quality with the view of increasing the satisfaction and thus usage, with positive impacts on increased public transport modal share and dropped CO2 emission transport. In total we have formed list of three main criteria: transport quality, service quality and traceability which contains in total 21 sub-criteria. For determining all criteria weights we have formed in total 112 models using IMF SWARA (Stepwise Weight Assessment Ratio Analysis) method and for final determining criteria weights Fuzzy Bonferroni operator (FBO) has been used. Applying such model we have ensured stability in final values of criteria and have obtained optimal results based on preferences decision makers. The adopted results show that the most significant attribute in the system is the “Traceability” with highest weight score (0.398), followed by the “Transport quality” with weight score (0.334), however, the service quality rank as the last significant attribute with weight score (0.264). The originality of our work is conducting IMF SWARA method for improving the service quality of the public transport system.
- СтавкаThe New New-Nacci Method for Calculating the Roots of a Univariate Polynomial and Solution of Quintic Equation in Radicals(MDPI, 2020) Tanackov, Ilija; Pavkov, Ivan; Stević, ŽeljkoAn arbitrary univariate polynomial of nth degree has n sequences. The sequences are systematized into classes. All the values of the first class sequence are obtained by Newton’s polynomial of nth degree. Furthermore, the values of all sequences for each class are calculated by Newton’s identities. In other words, the sequences are formed without calculation of polynomial roots. The New-nacci method is used for the calculation of the roots of an nth-degree univariate polynomial using radicals and limits of successive members of sequences. In such an approach as is presented in this paper, limit play a catalytic–theoretical role. Moreover, only four basic algebraic operations are sufficient to calculate real roots. Radicals are necessary for calculating conjugated complex roots. The partial limitations of the New-nacci method may appear from the decadal polynomial. In the case that an arbitrary univariate polynomial of nth degree (n 10) has five or more conjugated complex roots, the roots of the polynomial cannot be calculated due to Abel’s impossibility theorem. The second phase of the New-nacci method solves this problem as well. This paper is focused on solving the roots of the quintic equation. The method is verified by applying it to the quintic polynomial with all real roots and the Degen–Abel polynomial, dating from 1821.