New Model of Maximal Covering Location Problem with Fuzzy Conditions

The objective of Maximal Covering Location Problem is locating facilities such that they cover the maximal number of locations in a given radius or travel time. MCLP is applied in many different real-world problems with several modifications. In this paper a new model of MCLP with fuzzy conditions is presented. It uses two types of fuzzy numbers for describing two main parameters of MCLP - coverage radius and distances between locations. First, the model is defined, then Particle Swarm Optimization method for solving the problem is described and tested

USMENA PREDAJA U TURIZMU – SOCIO-DEMOGRAFSKA ANALIZA

In spite of the efforts of tourism marketers to encourage consumers to revisit particular tourist destinations, other factors contribute to this decision-making process. In this way, recommendations from family members and friends are considered to be trustful source of information in the process of choosing a tourist destination. Regardless of whether or not they have visited a tourist destination themselves, consumers recommend it to their family members and friends. This study represents an analysis of consumers’ socio-demographic characteristics (gender, age, education) differentiating between those who recommend, those who intend to recommend and those who do not. The aim of the paper is to point to the existence of differences of consumers in tourist destination decision making, according to socio-demographic characteristics of the respondents. The sample included 250 respondents from the territory of the Province of Vojvodina. In order to test proposed hypothesis statistical methods such as t test for independent samples and ANOVA were used. Key results of this research can be summarised as respondents in the sample do not show statistically significant differences in terms of demographic characteristics – gender, age and education level by any form of interpersonal behaviour and word-of-mouth communication in the process of choosing a tourist destination.Unatoč naporima marketinških eksperata u sektoru turizma u cilju poticanja turista-potrošača da ponovo posjete određenu turističku destinaciju, na tu njihovu odluku o kupovini utječu brojni drugi faktori. U tom smislu, preporuke članova obitelji i prijatelja se smatraju kao najpouzdaniji izvor informacija u procesu odluke i izbora turističke destinacije. Bez obzira jesu li tu turističku destinaciju doista posjetili ili nisu, potrošači često daju komentare i preporuke svojim članovima obitelji i svojim prijateljima. Ova istraživačka studija predstavlja analizu postojanja različitosti sociodemografskih karakteristika - spol, starost, obrazovanje kod turista - potrošača koji daju, namjeravaju dati, i koji ne daju preporuke, odnosno analizu razlika u preporukama potrošača prema socio-demografskim karakteristikama ispitanika. Uzorak istraživanja čini 250 ispitanika s područja Autonomne pokrajne Vojvodine. Sa ciljem da se testiraju predložene istraživačke hipoteze korištene su statističke metode kao što su t - test nezavisnih uzoraka i analiza varijance - ANOVA

Myocardial Infarction and Circadian Rhythm

Human physiological activity and condition during illness are under the control of the circadian rhythm. Circadian rhythms handle a wide diversity of physiological and metabolic functions, and the interruption of these rhythms has been linked to obesity, sleep disorders, metabolic and psychological disorders, and cardiovascular events such as myocardial infarction (MI), stroke, and vascular death. Disruption of circadian rhythms increases the risk of developing myocardial infarction, indicating that circadian genes might play an essential role in determining disease susceptibility. It is well known that many cardiovascular processes show daily variations depending on the circadian rhythm (blood pressure, heart rate), and the gene expression of the cardiomyocyte circadian clock influences myocardial contractile function, metabolism, and other gene expressions. We present a review of the latest knowledge on the impact of circadian rhythm and circadian rhythm genes on myocardial infarction. Today, in a time of personalized medicine, it is essential to know each person’s circadian rhythm for its treatment and possible inclusion in the diagnostic procedures

UTJECAJ EKOLOŠKI PRIHVATLJIVIH TRETMANA NA ANTIOKSIDACIJSKU AKTIVNOST U PLODOVIMA JAGODA TIJEKOM SKLADIŠTENJA

Proper postharvest storage is an effective way to maintain the quality and nutritional values of fruits. The aim of this study was to determine how environmentally friendly postharvest treatments with salicylic acid solution, colloidal silver solution and ozone, affect the antioxidant activity of strawberry fruits (Fragaria x ananassa Duch. cv. Albion) during 7 days of storage at 4°C. The content of ascorbic acid, total phenols and antioxidant activity of strawberry fruits were determined spec-trophotometrically. After 7 days of storage in strawberry fruits treated with all three treatments separately, the contents of ascorbic acid were higher than in the control fruits, supporting the usefulness of these treatments for preserving fruit quality and nutritional value during storage. The treatment with salicylic acid solution showed the most beneficial effect during storage causing a significant increase in the content of ascorbic acid, phenols and antioxidant activity at the end of the storage period.Pravilno skladištenje voća učinkovit je način za održavanje kvalitete i nutritivne vrijednosti plodova nakon berbe. Cilj ovog istraživanja bio je utvrditi kako ekološki prihvatljivi tretmani (otopina salicilne kiseline, otopina koloidnoga srebra i ozon) utječu na ukupnu antioksidacijsku aktivnost u plodovima jagoda (Fragaria x ananassa Duch.) sorte Albion tijekom 7 dana skladištenja pri 4°C. Koncentracije askorbinske kiseline, ukupnih fenola i ukupna antioksidacijska aktivnost u plodovima jagoda određeni su spektrofotometrijski. Svi primijenjeni tretmani prouzročili su povećanje koncentracije askorbinske kiseline u plodovima jagoda, što potvrđuje povoljno djelovanje navedenih tretmana na očuvanje kvalitete i nutritivne vrijednosti plodova. Tretman otopinom salicilne kiseline bio je najučinkovitiji, jer je prouzročio značajno povećanje koncentracije fenola, askorbinske kiseline i ukupne antioksidacijske aktivnosti na kraju perioda skladištenja

Genetic Algorithm Approach for Solving the Task Assignment Problem

This research was partially supported by the Serbian Ministry of Science and Ecology under project 144007. The authors are grateful to Ivana Ljubić for help in testing and to Vladimir Filipović for useful suggestions and comments.In this paper a genetic algorithm (GA) for the task assignment problem (TAP) is considered.An integer representation with standard genetic operators is used. Computational results are presented for instances from the literature, and compared to optimal solutions obtained by the CPLEX solver. It can be seen that the proposed GA approach reaches 17 of 20 optimal solutions. The GA solutions are obtained in a quite a short amount of computational time

The Use of Intelligent Packaging in Supply Chain of Food Products

The research aims to identify the limitations and expectations of producers, transport companies, distributors and retailers in introducing intelligent packaging into supply chains of food products on the market of the Western Balkans. The limitations and benefits from the use of intelligent packaging have been identified in transportation, storage, operations of physical handling and display of food products at the place of their final purchase. The results have shown that there are significant differences in terms of limitations affecting the implementation of intelligent packaging into business operations of supply chains, bearing in mind the business type, number of employees, available capital and integrated standards into business operations. In contrast to this, the results point that there are no significant differences in terms of benefits that the analysed entities expect from introducing intelligent packaging into their systems. A set of measures and incentives have been defined for the competent institutions and food supply chain management to take, in order to minimize the restrictions and advance the implementation of intelligent packaging. The proposals and suggestions for further research are stated in the paper.</p

A locally signed-distance preserving level set method (SDPLS) for moving interfaces

It is well-known that the standard level set advection equation does not preserve the signed distance property, which is a desirable property for the level set function representing a moving interface. Therefore, reinitialization or redistancing methods are frequently applied to restore the signed distance property while keeping the zero-contour fixed. As an alternative approach to these methods, we introduce a novel level set advection equation that intrinsically preserves the norm of the gradient at the interface, i.e. the local signed distance property. Mathematically, this is achieved by introducing a source term that is proportional to the local rate of interfacial area generation. The introduction of the source term turns the problem into a non-linear one. However, we show that by discretizing the source term explicitly in time, it is sufficient to solve a linear equation in each time step. Notably, without adjustment, the method works naturally in the case of a moving contact line. This is a major advantage since redistancing is known to be an issue when contact lines are involved (see, e.g., Della Rocca and Blanquart, 2014). We provide a first implementation of the method in a simple first-order upwind scheme.Comment: 18 pages, 5 figure

KOMUNIKACIJA I USAVRŠAVANJE KAO PREDIKTORI ODNOSA UČITELJA (SRPSKOG, HRVATSKOG I BOŠNJAČKOG ETNICITETA) PREMA DRUŠTVENIM SADRŽAJIMA U NASTAVI PRIRODE I DRUŠTVA

Istraživanje je imalo cilj da ispita doprinos dva značajna faktora, a to su međusobna komunikacija i stručno usavršavanje, formiranju odnosa učitelja različite etničke pripadnosti prema realizaciji društvenih sadržaja u nastavi prirode i društva. Uzorkom je obuhvaćen ukupno 301 učitelj srpske, hrvatske i bošnjačke nacionalnosti. Rezultati dobijeni ovim istraživanjem govore da razvijena komunikacija između učitelja, kroz svoje delovanje, doprinosi razvoju i unapređenju pozitivnih stavova prema društvenim sadržajima u nastavi prirode i društva, a što ima za posledicu povećanje efikasnosti vaspitno-obrazovnog procesa. Rezultatima je utvrđeno i da postoji statistički značajan doprinos predikciji stavova učitelja prema društvenim sadržajima u nastavi prirode i društva i od strane faktora stručnog usavršavanja, i to na taj način što izraženije prisustvo i kvalitet stručnog usavršavanja značajno deluje na razvoj i formiranje pozitivnih stavova prema sadržajima o društvu. Pored teorijskog rasvetljavanja uloge i značaja važnih koncepata koji su u vezi sa društvenim sadržajima i odnosom učitelja prema njima, u praktičnom smislu doprinos ovog istraživanja ogleda se u implikacijama značajnih veza među delovanjem različitih faktora u domenu vaspitno-obrazovnih ishoda u zemljama regiona (Srbija, Hrvatska i Bosna i Hercegovina). U skladu sa tim, praktične implikacije ukazuju na to da kroz obrazovne politike treba podsticati veću međusobnu komunikaciju među prosvetnim radnicima i omogućiti što bolje uslove za kontinuirano formalno i neformalno obrazovanje učitelja kroz celoživotno učenje u zemljama regiona

CO NSUMERS’ AGE AND WORD OF MOUTH

Turbulent marketing environment, where the consumers’ economic and social roles in general are transforming, has caused businesses to accept the fact that consumer choice and decision making comprise a single social process, which does not depend only on the impact of companies’ marketing mix elements on the consumers, but that this complex process is most determined by individual or group-based interactions and relationships between the consumers themselves through word-of-mouth communication. Consumer behaviour at the market is determined by many factors, and is therefore characterized as very complex and difficult to predict. Consumers’ age is one amongst many important factors that marketing theory and practice research on a daily basis. This paper attempts to address the impact of consumers’ age on creation and diffusion of word of mouth resulting in purchase decision, and tries to point out some directions of thinking and future research, based on the experience from the Republic of Serbia

OPINION LEADERS - OPPORTUNITY OR THREAT FOR THE COMPANY?

Contemporary business conditions set up a new complex problem for the companies – a dramatic decline in the return on investment of different types of promotion activities. Consumers on the global market are showing increasing levels of resistance and lack of confidence in a growing number of marketing messages sent to them by companies, mostly because those messages communicate only on the positive and often embellished aspects of the products and services. Consumers wishing to reduce the risk of wrong purchase decisions are turning to other consumers in whose advice and attitudes they have confidence, and thus get a true picture of the market situation. Those consumers are very specific individuals recognized as opinion leaders in marketing literature. In this way, the company’s control on consumer purchase decision is reduced significantly, thereby increasing the overall risk of doing business. The paper aims to highlight the importance of the research of consumer opinion leaders in marketing theory and practice, to identify their characteristics and behaviour, and to point out possible ways of their identification. The empirical research will test the hypothesis of the existence of the gender impact on consumer display of opinion leadership in the Republic of Serbia