The k-LEAF OUT-BRANCHING problem is to find an out-branching, that is a rooted oriented spanning tree, with at least k leaves in a given digraph. The problem has recently received much attention from the viewpoint of parameterized algorithms. Here, we take a kernelization based approach to the k-LEAF-OUTBRANCHING problem. We give the first polynomial kernel for ROOTED k-LEAF-OUT-BRANCHING, a va...

the aim of this study was to determine the relationship between entrepreneurial personality characteristics and small and medium-sized sport enterprises start-up (smses). the methodology of this study was descriptive-correlation. population consisted of small and medium-sized sport enterprises (n=1500) and their owners and/or managers were randomly selected as the sample (n=258). for data colle...

The Energy Storage System (ESS) is an expensive component of an E-bike. The idea of Hybrid Energy Storage System (HESS), a combination between battery and Ultra-Capacitor (UC), can moderate the cost of E-bike ESS. In this paper, a cost function is developed to use for optimal sizing of a HESS. This cost function is consisted of the HESS (battery, UC and DC/DC converter) cost and the cost of bat...

Nowadays, we are witnessing the growth of firms that distribute the production capacity of their products to a wide geographic range to supply the demand of several markets. In this article, the relationships and interactions between cell design and supply chain design are investigated. For this purpose, a novel integrated model is presented for designing dynamic cellular manufacturing systems ...

With today's development of information technology comes the increased development of numerous real-time multimedia network applications. Some examples include video and tele-conferencing, tele-medicine, video-on-demand, distance education, applications in finance, etc. Several of these applications require multicasting with a certain Quality of Service (QoS). One of the most important QoS para...

Travelling salesman problem (TSP) is a combinatorial optimization problem. It is NP hard problem and TSP is the most intensively studied problem in the area of optimization. There are a number of approximation algorithms and heuristics proposed in the literature which can yield to good solutions. But with the increase in the number of cities, the complexity of the problem goes on increasing. Th...

Railway scheduling is a complex task of rail operators that involves the generation of a conflict-free train timetable. This paper presents a discrete-event simulation-based optimization approach for solving the train timetabling problem to minimize total weighted unplanned stop time in a hybrid single and double track railway networks. The designed simulation model is used as a platform for ge...

The navigation of autonomous mobile machines, which are referred to as robots, through unknown terrains, i.e., terrains whose models are not a priori known is considered. We deal with point-sized robots in twoand three-dimensional terrains and circular robots in two-dimensional terrains. The two-dimensional (three-dimensional) terrains are finite-sized and populated by an unknown, hut, finite, ...

Regarding the development of distribution systems in the recent decades, fuel consumption of trucks has increased noticeably, which has a huge impact on greenhouse gas emissions. For this reason, the reduction of fuel consumption has been one of the most important research areas in the last decades. The aim of this paper is to propose a robust mathematical model for a variant of a vehicle routi...