Guided vehicles (GVs) are commonly used for the internal transportation of loads in warehouses, production plants and terminals. These guided vehicles can be routed with a variety of vehicle dispatching rules in an attempt to meet performance criteria such as minimizing the average load waiting times. In this research, we use simulation MODELs of three companies to evaluate the performance of several real-time vehicle dispatching rules, in part described in the literature. It appears that there is a clear difference in average load waiting time between the different dispatching rules in the different environments. Simple rules, based on load and vehicle proximity (distance-based) perform best for all cases. The penalty for this is a relatively high maximum load waiting time. A distance-based rule with time truncation, giving more priority to loads that have to wait longer than a time threshold, appears to yield the best possible overall performance. A rule that particularly considers load-waiting time performs poor overall. We also show that using little pre-arrival information of loads leads to a significant improvement in the performance of the dispatching rules without changing their performance ranking.
标签： Testing and classifying vehicle dispatching rules in three real-world settings
上传时间： 2016-04-01
上传用户：五块钱的油条
Computational MODELs are commonly used in engineering design and scientific discovery activities for simulating complex physical systems in disciplines such as fluid mechanics, structural dynamics, heat transfer, nonlinear structural mechanics, shock physics, and many others. These simulators can be an enormous aid to engineers who want to develop an understanding and/or predictive capability for complex behaviors typically observed in the corresponding physical systems. Simulators often serve as virtual prototypes, where a set of predefined system parameters, such as size or location dimensions and material properties, are adjusted to improve the performance of a system, as defined by one or more system performance objectives. Such optimization or tuning of the virtual prototype requires executing the simulator, evaluating performance objective(s), and adjusting the system parameters in an iterative, automated, and directed way. System performance objectives can be formulated, for example, to minimize weight, cost, or defects; to limit a critical temperature, stress, or vibration response; or to maximize performance, reliability, throughput, agility, or design robustness. In addition, one would often like to design computer experiments, run parameter studies, or perform uncertainty quantification (UQ). These approaches reveal how system performance changes as a design or uncertain input variable changes. Sampling methods are often used in uncertainty quantification to calculate a distribution on system performance measures, and to understand which uncertain inputs contribute most to the variance of the outputs. A primary goal for Dakota development is to provide engineers and other disciplinary scientists with a systematic and rapid means to obtain improved or optimal designs or understand sensitivity or uncertainty using simulationbased MODELs. These capabilities generally lead to improved designs and system performance in earlier design stages, alleviating dependence on physical prototypes and testing, shortening design cycles, and reducing product development costs. In addition to providing this practical environment for answering system performance questions, the Dakota toolkit provides an extensible platform for the research and rapid prototyping of customized methods and meta-algorithms
标签： Optimization and Uncertainty Quantification
上传时间： 2016-04-08
上传用户：huhu123456
Color appearance MODELs aim to extend basic colorimetry to the level of specifying the perceived color of stimuli in a wide variety of viewing conditions
标签： appearance Color model
上传时间： 2016-05-21
上传用户：wisewater
Dynasty 350, 700 208/575 Volt MODELs W/Auto-Line Maxstar 350, 700 File: TIG (GTAW) Including Optional Cart And Cooler CE And Non-CE MODELs
上传时间： 2017-03-11
上传用户：zosoong
深度学习，神经网络，卷积神经网络 Analysis of Deep Learning MODELs using CNN Techniques
上传时间： 2020-01-02
上传用户：wzy2020
The current methods of communications are becoming less relevant under today’s growing demand for and reliance on constant connectivity. Of decreasing relevance are the MODELs of a single radio to perform a single task. The expansion of wireless access points among coffee shops, airports, malls, and other public arenas is opening up opportunities for new services and applications.
上传时间： 2020-05-26
上传用户：shancjb
In 2005, when the world crossed-over to Web 2.0, business professionals and managers in every industry – from traditional retail to high tech media and telecom – felt the first powerful tremors of the strategic shifts taking place, sweeping away traditional business MODELs and altering competitive landscapes.
上传时间： 2020-05-27
上传用户：shancjb
Throughout the course of my work in multihop mobile ad hoc networks (MANET) over the last several years, I reached the conclusion that mobility MODELs and perfor- mance metrics need to be treated in detail in designing these networks that are the ultimatefrontierinwirelesscommunications. AwidevarietyofmobilityMODELscan be used by mobile nodes.
标签： Handbook Networks Mobility Mobile MODELs Hoc for Ad of
上传时间： 2020-05-27
上传用户：shancjb
With the rapid expansion of wireless consumer products,there has been a con- siderable increase in the need for radio-frequency (RF) planning, link plan- ning, and propagation modeling.A network designer with no RF background may find himself/herself designing a wireless network. A wide array of RF planning software packages can provide some support, but there is no substi- tute for a fundamental understanding of the propagation process and the lim- itations of the MODELs employed. Blind use of computer-aided design (CAD) programs with no understanding of the physical fundamentals underlying the process can be a recipe for disaster. Having witnessed the results of this approach, I hope to spare others this frustration.
标签： Introduction Propagation to RF
上传时间： 2020-05-27
上传用户：shancjb
When we started thinking about writing the first edition of this book a few years ago, we had been working together for more than five years on the borderline between propagation and signal processing. Therefore, it is not surprising that this book deals with propagation MODELs and design tools for MIMO wireless communications. Yet, this book should constitute more than a simple combination of these two domains. It hopefully conveys our integrated understanding of MIMO, which results from endless controversial discussions on various multi-antenna related issues, as well as various interactions with numerous colleagues. Obviously, this area of technology is so large that it is beyond our aim to cover all aspects in details. Rather, our goal is to provide researchers, R&D engineers and graduate students with a comprehensive coverage of radio propagation MODELs and space–time signal processing techniques for multi-antenna, multi-user and multi-cell networks.
上传时间： 2020-05-28
上传用户：shancjb
