Simulation for Transport Pallet Cost Reduction in Pet Food Manufacturing: An Empirical Case Study

This study examined different managerial scenarios for the cost reduction of transport pallets rented by a pet food manufacturer that produces pet food sold in local and international markets. A computer simulation model was developed on the basis of the empirical case to analyse the flow of pallets from the factory, the subcontractors and the distribution centre and to determine the system performance measures in terms of the average waiting times and the number of pallets in queues. The analysis showed that problems occurred when slow‐moving products occupied the rental pallets for a long time and because too much inventory was kept at the distribution centre. Two managerial scenarios were then proposed to alleviate these problems, involving pallet movement decisions by internal management. The results suggested a choice of decision supports to determine which managerial scenario was suitable for the business. The proposed implications may be beneficial to similar industries where a supply system of rental pallet service is applied. Copyright © 2011 John Wiley & Sons, Ltd.     

Crystallization behavior of plasticized poly(lactide) film by poly(l-lactic acid)-poly(ethylene glycol)-poly(l-lactic acid) triblock copolymer

Polymer Bulletin - Poly(l-lactic acid)-poly(ethylene glycol)-poly(l-lactic acid) triblock copolymer (PLLA-PEG-PLLA) prepared by simple esterification of l-lactic acid (l-LA) and diol-polyethylene...     

Location- and delay-aware cross-layer communication in V2I multihop vehicular networks

Intelligent transportation systems are targeted to improve the traffic safety and driving experience of passengers. Vehicular ad hoc networks are wireless communication networks proposed to be used as parts of ITS. VANETs facilitate communication among vehicles, and between vehicles and roadside equipment. A key challenge in developing such systems is to design routing and MAC protocols that not only provide good end-to-end packet delay but can also quickly adapt to changes in the network topology due to vehicular mobility. In this article we outline a new framework for location- and delayaware cross-layer communication that addresses these challenges. Our framework provides an efficient V2I data delivery system that relays packets over low-delay paths to a fixed base station or access point. Furthermore, an instance of this framework is also presented as a protocol. Our preliminary evaluations show that our design approach is promising, and provides delay predictability, fairness, and a good packet delivery ratio.     

A survey of cross-layer design for VANETs

Recently, vehicular communication systems have attracted much attention, fueled largely by the growing interest in Intelligent Transportation Systems (ITS). These systems are aimed at addressing critical issues like passenger safety and traffic congestion, by integrating information and communication technologies into transportation infrastructure and vehicles. They are built on top of self organizing networks, known as a Vehicular Ad hoc Networks (VANET), composed of mobile vehicles connected by wireless links. While the solutions based on the traditional layered communication system architectures such as OSI model are readily applicable, they often fail to address the fundamental problems in ad hoc networks, such as dynamic changes in the network topology. Furthermore, many ITS applications impose stringent QoS requirements, which are not met by existing ad hoc networking solutions. The paradigm of cross-layer design has been introduced as an alternative to pure layered design to develop communication protocols. Cross-layer design allows information to be exchanged and shared across layer boundaries in order to enable efficient and robust protocols. There has been several research efforts that validated the importance of cross-layer design in vehicular networks. In this article, a survey of recent work on cross-layer communication solutions for VANETs is presented. Major approaches to cross-layer protocol design is introduced, followed by an overview of corresponding cross-layer protocols. Finally, open research problems in developing efficient cross-layer protocols for next generation transportation systems are discussed.