Deposit return systems have started making their reappearance as more environmentally conscious consumers seek ways to effectively reduce their carbon footprint. An example is the management of refillable glass bottle...
详细信息
Deposit return systems have started making their reappearance as more environmentally conscious consumers seek ways to effectively reduce their carbon footprint. An example is the management of refillable glass bottles which requires a well-organized collection network with inventory management. A collection planning with an efficient algorithm and information system has to be applied. This paper investigates, using integer linear programming, a vehicle routing problem with time constraints to provide flexibility as well as priority rules to avoid inventory saturation at collection points. The model presented, based on a real-life application in the city of Lyon and surrounding areas, includes several objectives with specific assumptions. The result of the optimization is a vehicle routing plan with flexible scheduling based on time slots. Numerical experiments are conducted on instances of different scales making it possible to model the current problem as well as its future evolution. These experiments consider several instances, using a single vehicle among three vehicle types (cargo-bicycle, car and van) and a network composed of 20 stores/clients to collect bottles from. The results show the impacts of the priority rules on the solution obtained and additional indicators are proposed in order to analyze more precisely the quality of the solution in terms of financial cost and environmental impact. The proposed model and program will help make appropriate decisions in planning and scheduling the routes of the vehicles for the refillable glass bottle collection, especially in urban areas.
The present paper explores a Greek case study on optimizing the design of aviation networks under Public Service Obligations (PSO). Based on previous research on airline PSO networks applied to the case studies of the...
详细信息
The present paper explores a Greek case study on optimizing the design of aviation networks under Public Service Obligations (PSO). Based on previous research on airline PSO networks applied to the case studies of the Azores and Norway, optimization models are adapted to minimize not only the cost to the airline, but also the total social costs. Different predictive models to estimate demand are developed and included in the optimization models. It is found that after applying the developed demand and optimization models, the total network costs can be reduced significantly, compared to the actual network?s operation ranging from 4% to 20%.
This paper presents a new multi-criteria decision model for the material handling device (MHD) selection problem in cellular manufacturing systems. Given a set of manufacturing cells based on several automatic work-ce...
详细信息
In interconnection networks, matching preclusion is a measure of robustness when there is a link failure. Let G be a graph with an even number of vertices. A set of edges of G is called a matching preclusion set if it...
详细信息
Mapping a real-time embedded application onto a multiprocessor architecture under several constraints such as performance, cost, energy, and reliability is a major challenge in embedded systems. In this paper, we pres...
详细信息
ISBN:
(纸本)0780392647
Mapping a real-time embedded application onto a multiprocessor architecture under several constraints such as performance, cost, energy, and reliability is a major challenge in embedded systems. In this paper, we present an ILP (integer linear programming) based framework that maps a given application (represented as a task graph) onto an HCM (Heterogeneous Chip Multiprocessor) architecture. Our framework can be used with several objective functions such as energy, performance, and fallibility (opposite of reliability). We use Dynamic Voltage Scaling (DVS) for reducing energy consumption while we employ task duplication to minimize fallibility.
Demands for avionics Wavelength Division Multiplexing (WDM) network have been increasing dramatically in multicasting applications such as the in-flight multimedia in recent years. The topic of multicasting routing pr...
详细信息
ISBN:
(纸本)9781467316996
Demands for avionics Wavelength Division Multiplexing (WDM) network have been increasing dramatically in multicasting applications such as the in-flight multimedia in recent years. The topic of multicasting routing problem has been investigated with enthusiasm, because a proper design of routing can not only make full use of the resource, but also improve the performance of networks. However, different from other WDM networks like the backbone WDM network or the WDM LAN, the requirements of reliability and predictability of avionics WDM network are far stricter. In this article, we study light-trees optimization that aim to minimize the cost of the network after giving the general problem definition. In order to expand our work, we first propose the integer linear programming (ILP) algorithms for a simple situation without traffic grooming. Then we consider a more practical situation on the basis of this algorithm. By analyzing three schemes for supporting multicast connections, we select Stop-and-Go (S/G) Light-tree because it can save resource and meanwhile decrease the delay of messages. We also propose an integer linear programming algorithm for this scenario. This algorithm focuses on: 1) the delay constraint, which means sessions need to arrive at destination in limited time;2) the load constraint to meet the requirement of reliability;3) sparse splitting constraint, i.e., some switches are incapable of splitting light because of economical reason. The simulation results of WDM network show the algorithm can minimize the cost while ensure the timing requirement.
State assignment for finite state machines is a critical optimization problem in the synthesis of sequential circuits. In this paper we address the state assignment problem from a low power perspective. We experiment ...
详细信息
ISBN:
(纸本)9781424457939
State assignment for finite state machines is a critical optimization problem in the synthesis of sequential circuits. In this paper we address the state assignment problem from a low power perspective. We experiment with Boolean Satisfiability and integer linear programming techniques to solve the assignment problem where the primary goal is the reduction of switching activity during state transitions. We also detect and evaluate the use of symmetries in speeding up the search process. These techniques have been applied to the MCNC benchmark circuits and yielded promising results.
In this paper we present an algorithm, based on power management of Access Points (AP), to reduce congestion in Wireless Local Area Networks (WLANs). The algorithm finds the Most Congested Access Point (MCAP) and adju...
详细信息
In this paper we present an algorithm, based on power management of Access Points (AP), to reduce congestion in Wireless Local Area Networks (WLANs). The algorithm finds the Most Congested Access Point (MCAP) and adjusts its transmitted power in discrete steps and determines the optimal users' assignment such that an optimal load distribution is achieved. Results show that the algorithm is capable of significantly reducing the overall congestion in the WLAN.
Analog-to-digital converters based on sigma-delta modulation have shown promising performance, with steadily increasing bandwidth. However, associated with the increasing bandwidth is an increasing output sample rate,...
详细信息
Analog-to-digital converters based on sigma-delta modulation have shown promising performance, with steadily increasing bandwidth. However, associated with the increasing bandwidth is an increasing output sample rate, which becomes costly to decimate in the digital domain. Commonly, cascaded integrator comb structures have been used for the first decimation stage, but polyphase decomposed FIR filter architectures have been shown to be more power efficient. In this paper, a bit-level optimization algorithm is introduced, and applied to the direct form and transposed form FIR filter architectures. Mainly, two conclusions can be drawn. The transposed architecture has significantly lower complexity in most circumstances, and the inability to implement an efficient adder prohibits the symmetry of the filter coefficients to be used efficiently for the direct form architecture.
暂无评论