13 research outputs found
Eating patterns of Turkish adolescents: a cross-sectional survey
<p>Abstract</p> <p>Background</p> <p>Adolescence is a crucial period for development of dietary behaviors that continue into adulthood and influence the risk of chronic diseases later in life. The aim of this study was to determine the eating patterns of adolescents' and their compliance with the Food Guide Pyramid.</p> <p>Methods</p> <p>625 students, aged between 11-15 years, from an elementary school in Istanbul, Turkey were enrolled in this cross-sectional survey. A questionnaire of eating patterns (QEP) was administered to all participants. QEP is consisted of questions assessing the knowledge and behaviors on healthy eating, factors affecting food choice, physical activity status and demographical variables. Height and weight of all participants were measured. Physical activity status was determined by questioning about participation in regular sport activities, how much time spent watching TV, playing computer games or doing homework.</p> <p>Results</p> <p>The mean age of the participants was 12.15 ± 1.15 and 50.5% were female. According to body mass index (BMI) percentiles, 8.3% (52) were obese and 10.2% were overweight. 51% had breakfast every day and only 1.9% met all the recommendations of the Food Guide Pyramid. Among the participants, 31% have fast food at least once every day and 60.8% skip meals. When participants were asked to rate the factors effecting their food choice according to a 10 point Likert scale, the highest mean scores (high impact on food choice) were for the factors; family, health, body perception, teachers and friends; 7.5 ± 3.1, 7.4 ± 3.1, 6.1 ± 3.2, 4.8 ± 3.3 and 4.2 ± 3.0 respectively. Total mean time spent on all passive activities (TV, computer, reading homework etc) per day was 9.8 ± 4.7 hours.</p> <p>Conclusions</p> <p>In this study we have demonstrated that, adolescents do not have healthy eating patterns. Educational interventions should be planned to decrease the health risks attributable to their eating behaviors.</p
On The Characterizations of The Interval Sequential Equal Contributions Rule
Abstract: This paper deals with the research area of cooperative interval games arising from airport situations with interval data. The major topic of the paper is to present and introduce the interval sequential equal contributions rule. The main result of this study is to give an axiomatic characterization of the interval sequential equal contributions rule.
Key words: airport situations, sequential equal contributions rule, interval data.
Aralıklı Ardışık Eşit Dağıtım Kuralının Karakterizasyonları Üzerine
Özet: Bu makale aralıklı havaalanı durumlarından ortaya çıkan işbirlikçi aralıklı oyunları araştırmak üzerine yazılmıştır. Bu makalenin en büyük katkısı aralıklı ardışık eşit dağıtım kuralından ilk defa bahsetmektir. Bu çalışmanın en önemli sonucu ise aralıklı ardışık eşit dağıtım kuralının aksiyomatik olarak karakterize edilmesidir.
Anahtar Kelimeler: havaalanı durumları, ardışık eşit dağıtım kuralı, aralık kavramı
An Axiomatization of the Interval Shapley Value and on Some Interval Solution Concepts
The Shapley value, one of the most common solution concepts in Operations Research applications of cooperative game theory, is defined and axiomatically characterized in different game-theoretical models. In this paper, we focus on the Shapley value for cooperative games where the set of players is finite and the coalition values are compact intervals of real numbers. In this study, we study the properties of the interval Shapley value on the class of size monotonic interval games, and axiomatically characterize its restriction to a special subclass of cooperative interval games by using fairness property, efficiency and the null player property. Further, we introduce the interval Banzhaf value and the interval egalitarian rule. Finally, the paper ends with a conclusion and an outlook to future studies
Cooperative games under bubbly uncertainty
The allocation problem of rewards/costs is a basic question for players, namely, individuals and companies that are planning cooperation under uncertainty. The involvement of uncertainty in cooperative game theory is motivated by the real world in which noise in observation and experimental design, incomplete information and vagueness in preference structures and decision-making play an important role. In this study, a new class of cooperative games, namely, the cooperative bubbly games, where the worth of each coalition is a bubble instead of a real number, is presented. Furthermore, a new solution concept, the bubbly core, is defined. Finally, the properties and the conditions for the non-emptiness of the bubbly core are given. The paper ends with a conclusion and an outlook to related and future studies
An Application of Cooperative Grey Games to Post-Disaster Housing Problem
This paper shows that cooperative grey game theory can help us to establish a fair cost share between private organizations for supporting the temporary housing problem by using facility location games under uncertainty. Temporary accommodation may be a method that ought to get started before the tragedy happens, as a preventative pre-planning. In spite of being temporary constructions, the housing buildings are one of the most essential parts to produce in emergency situations, to contribute to the reconstruction and to recover better. Our study is based on a default earthquake in Izmir of western Turkey. A number of tents are being built in the following three cities, Aydin, Usak, and Balikesir near Izmir as illustrated in Figure 1. Two companies are selected, one is local and another is foreign to distribute the tents in a fair way between the three cities. For this purpose, we use cooperative grey game theory to help us to define a fair cost allocation between private organizations for supporting the housing problem by using facility location games under uncertainty
On the Grey Equal Surplus Sharing Solutions
The grey uncertainty is a new methodology focusing on the study of problems involving small samples and poor information. It deals with uncertain systems with partially known information through generating, excavating, and extracting useful information from what is available. This paper focuses some division solutions for cooperative games, called the equal surplus sharing solutions. A situation, in which a finite set of players can obtain certain grey payoffs by cooperation can be described by a cooperative grey game. In this paper, we consider some grey division rules, namely the equal surplus sharing grey solutions. Further, we focus on a class of equal surplus sharing grey solutions consisting of all convex combinations of these solutions. An application from Operations Research (OR) situations is also given
Transportation interval situations and related games
Basically, uncertainty is present in almost every real-world situation, it is influencing and questioning our decisions. In this paper, we analyze transportation interval games corresponding to transportation interval situations. In those situations, it may affect the optimal amount of goods and consequently whether and how much of a product is transported from a producer to a retailer. Firstly, we introduce the interval Shapley value of a game arising from a transportation situation under uncertainty. Secondly, a one-point solution concept by using a one-stage producere depending on the proportional, the constrained equal awards and the constrained equal losses rule is given. We prove that transportation interval games are interval balanced (I-balanced). Further, the nonemptiness of the interval core for the transportation interval games and some results on the relationship between the interval core and the dual interval optimal solutions of the underlying transportation situations are also provided. Moreover, we characterize the interval core using the square operator and addressing two scenarios such as pessimistic and optimistic
Airport Situations and Games with Grey Uncertainty
In this work, we deal with airport situations where the costs of the pieces of the runway are given by grey numbers. In this context, we expand the Baker-Thompson rule as a solution concept. Some properties regarding an allocation problem of an airport situation under uncertainty is considered and grey solutions are proposed. We introduce grey Baker-Thompson rule. Further, we give the axiomatic characterization of the grey Baker-Thompson rule by using the major and the minor axioms
Cooperative Grey Games: Grey Solutions and an Optimization Algorithm
In this paper, some set-valued solutions using grey payoffs, namely, the grey core, the grey dominance core and the grey stable sets for cooperative grey games, are introduced and studied. Our main results contained are relations between the grey core, the grey dominance core and the grey stable sets of such a game. Moreover, we present a linear programming (LP) problem for the grey core. On the other hand, we suggest a corresponding optimization-basedalgorithm finding the grey core element of a cooperative grey game. Finally, we give an application how cooperative grey game theory can be used to model users' behaviors in various multimedia social networks. The paper ends with aconclusion and an outlook to future investigations