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31.
基于Petri网的物流分拣系统的建模与仿真   总被引:4,自引:0,他引:4  
阐述了面向对象着色Petri网理论,并将它应用于物流分拣系统的建模,在分析该系统的基础上,建立了系统的面向对象着色Petri网模型,并借助AutoMod仿真软件对分拣系统进行了3D仿真。  相似文献   
32.
Foresight activities have often provided support for objectives such as priority-setting, networking and consensual vision-building. In this paper, we draw upon complementary evolutionary perspectives and discuss these objectives from the viewpoint of diversity which may be vital in contexts characterized by technological discontinuities and high uncertainties. We also argue that although the scanning of weak signals has been widely advocated in such contexts, the solicitation of ideas for prospective innovations may provide more focused, action-oriented, and comparable reflections of future developments. For the analysis of such ideas, we develop a collaborative foresight method RPM Screening which consists of phases for the generation, revision, multi-criteria evaluation, and portfolio analysis of innovation ideas. We also report experiences from a pilot project where this method was employed to enhance the work of the Foresight Forum of the Ministry of Trade and Industry in Finland. Encouraging results from this project and other recent applications suggest that RPM Screening can be helpful in foresight processes and the development of shared research agendas.  相似文献   
33.
近年来,中国的肥胖儿童不断增多。由于该现象发生在“独生子女”政策开始实施以后,后者被认为是前者之因。然而,实证研究的缺乏使生育政策与儿童营养过剩之间的关系尚不明确。使用“中国健康和营养调查”数据,探讨政策与儿童(0-12岁)营养过剩之间的关系。多层模型和纵向分析结果显示,其一,儿童营养过剩的比例在90年代持续攀升,但增长速度较慢。其二,虽然生活在一孩生育政策地区的儿童营养过剩的比例高于其它地区儿童,独生子女营养过剩的比例超过非独生子女,但在其它条件同等的情况下,生育政策的地区差异和姊妹结构与儿童营养过剩概率无显著关联。分析结果并不支持“独生子女政策造成了儿童肥胖”的公共观点。影响儿童营养过剩的主要因素包括父母的体重、母亲的教育、社区发展水平和省份。  相似文献   
34.
论述了经济系统中数学模型的建立问题,并对数学建模过程进行了理论分析。  相似文献   
35.
本文提出了晶体和频率控制元件的模型,介绍了基本电路的设计,并详细讨论了压控晶体振荡器调制器产生最小音频失真的必要条件。  相似文献   
36.
The Dynamics of Location in Home Price   总被引:4,自引:1,他引:4  
It is well established that house prices are dynamic. It is also axiomatic that location influences such selling prices, motivating our objective of incorporating spatial information in explaining the evolution of house prices over time. In this paper, we propose a rich class of spatio-temporal models under which each property is point referenced and its associated selling price modeled through a collection of temporally indexed spatial processes. Such modeling includes and extends all house price index models currently in the literature, and furthermore permits distinction between the effects of time and location. We study single family residential sales in two distinct submarkets of a metropolitan area and further categorize the data into single- and multiple-transaction observations. We find the spatial component is very important in explaining house price. Moreover, the relative homogeneity of homes within the submarket and the frequency with which homes sell affects the pattern of variation across space and time. Differences between single and repeat sale data are evident. The methodology is applicable to more general capital asset pricing when location is anticipated to be influential.  相似文献   
37.
Machine learning techniques make it feasible to calculate claims reserves on individual claims data. This paper illustrates how these techniques can be used by providing an explicit example in individual claims reserving.  相似文献   
38.
In this paper, we study the family of renewal shot-noise processes. The Feynmann–Kac formula is obtained based on the piecewise deterministic Markov process theory and the martingale methodology. We then derive the Laplace transforms of the conditional moments and asymptotic moments of the processes. In general, by inverting the Laplace transforms, the asymptotic moments and the first conditional moments can be derived explicitly; however, other conditional moments may need to be estimated numerically. As an example, we develop a very efficient and general algorithm of Monte Carlo exact simulation for estimating the second conditional moments. The results can be then easily transformed to the counterparts of discounted aggregate claims for insurance applications, and we apply the first two conditional moments for the actuarial net premium calculation. Similarly, they can also be applied to credit risk and reliability modelling. Numerical examples with four distribution choices for interarrival times are provided to illustrate how the models can be implemented.  相似文献   
39.
In order to enhance performance, manufacturing firms are building various capabilities and utilizing supply chain networks that are geographically dispersed around the globe. This study examines how decisions related to supply chain architecture and product architecture influence organizational competitiveness. Building on the co-specialization perspective, we evaluate the performance implications of product modularity and supply chain agility. While, product modularity constitutes a product configuration related to sourcing and assembling of products, supply chain agility is a supply chain configuration related to velocity (sensing, comprehending, and responding) and visibility (supplier network, internal operations, and external environment). Both the product and supply chain architectural decisions can impact performance, individually and in conjunction with each other. We empirically test the hypothesized relationships using data collected from 103 manufacturing firms. Results show that supply chain agility and product modularity directly enhance responsiveness and enable organizations to reduce cost. Furthermore, supply chain agility partially mediates the relationship between product modularity and both responsiveness and cost reduction. We elaborate on the key contributions of this study for both research and practice, discuss limitations, and also offer various avenues for further research.  相似文献   
40.
本文阐述了在Arduino UNO上对MiFare One卡射频识别卡进行读写的软件实现,并重点描述了阅读器与卡片之间的通信过程。  相似文献   
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