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261.
甄瑞卿 《铁道劳动安全卫生与环保》2007,34(5):228-231
印刷行业数量众多,分布广泛,其环境有害因素不容忽视。印刷业中,原稿、胶片、印版、油墨和润版液等原材料的使用构成了印刷工艺的全过程。印刷中有的组成了印刷产品的一部分,有的在使用中或用毕废弃后则以固态、液态或气态的形式污染环境。应大力提倡环保型印刷材料和工艺的研究和推广,加强企业QMS、EMS和OHSMS科学管理体系的建设,在实施PDCA循环管理的基础上,使各种环境有害因素得到不断控制和减少。 相似文献
262.
山区河流渠化枢纽布置模糊综合评判 总被引:3,自引:1,他引:2
山区河流渠化布置是较复杂的问题,涉及影响因子较多,其中大多具有不能定量模糊因素。运用模糊数学思想,把模糊评判引入到山区渠化枢纽布置选优中,对选优前各个方案进行模糊评判,以期提供一种分析问题的思路。 相似文献
263.
计算机配色中活性染料单位浓度K/S值研究 总被引:1,自引:0,他引:1
在计算机自动配色中,所用染料的单位浓度K/S值准确与否,直接影响配色精度。提出的单位浓度K/S值算法思想是,通过引进调整系数,根据不同浓度梯度对光谱数据进行合理的调整,使库贝尔卡-芒克函数与浓度具有更好的线性关系。在实例分析中,用3组活性染料按不同浓度梯度对纯棉织物进行染色,应用最优化方法确定光谱数据的调整系数,进而求解所用染料的单位浓度K/S值,最后由三刺激值匹配算法得出预测配方,并使用CIE1976(L^*,a^*,b^*)均匀颜色空间色差公式来衡量配色效果。实验证明,配色的预测结果能够较好地满足计算机配色的要求。 相似文献
264.
Effect of attitudes, habit and affective appraisal on mode choice: an application to university workers 总被引:1,自引:0,他引:1
Traditionally, car use and modal choice, in general, have been studied under the random utility framework, assuming that individuals
choose a particular mode based on their own socio-economic characteristics and the attributes describing the available options.
This approach has originated useful models which have been able to explain modal split. However, at the same time, it has
received critics because of its poor characterization of human behaviour and the weakness of its assumptions. Research has
suggested that socio-psychological factors could help to understand better the choice process. In this paper, attitudinal
theory and its link to human behaviour were used to select attitudes, habit and affective appraisals as explanatory variables.
They were measured using ad-hoc instruments, which were combined with a revealed preference questionnaire, in order to obtain
information about the traveller and the chosen mode. This instrument was applied to a sample extracted from staff members
of the University of Concepcion, Chile. Analyses of attitudinal variables showed that car use habit was positively correlated
to attitude and positive emotions towards car, implying that breaking the vicious circle of car use through persuasive techniques
might be difficult. Estimation of discrete choice models showed that attitudinal variables presented a significant contribution
to modal utility, and helped to improve both fitness and statistical significance. Results showed that choice can be influenced
by factors related to attitudes and affective appraisal, and that their study is necessary in order to achieve an effective
car use reduction.
相似文献
Alejandro TudelaEmail: |
265.
A probabilistic framework for weather-based rerouting and delay estimations within an Airspace Planning model 总被引:1,自引:0,他引:1
Michael V. McCrea Hanif D. Sherali Antonio A. Trani 《Transportation Research Part C: Emerging Technologies》2008,16(4):410-431
In this paper, we develop a novel severe weather-modeling paradigm to be applied within the context of a large-scale Airspace Planning and collaborative decision-making model in order to reroute flights with respect to a specified probability threshold of encountering severe weather, subject to collision safety, airline equity, and sector workload considerations. This approach serves as an alternative to the current practice adopted by the Federal Aviation Administration (FAA) of adjusting flight routes in accordance with the guidelines specified in the National Playbook. Our innovative contributions in this paper include (a) the concept of “Probability-Nets” and the development of discretized representations of various weather phenomena that affect aviation operations; (b) the integration of readily accessible severe weather probabilities from existing weather forecast data provided by the National Weather Service; (c) the generation of flight plans that circumvent severe weather phenomena with specified probability threshold levels, and (d) a probabilistic delay assessment methodology for evaluating planned flight routes that might encounter potentially disruptive weather along its trajectory. Additionally, we conduct an economic benefit analysis using a k-means clustering mechanism in concert with our delay assessment methodology in order to evaluate delay costs and system disruptions associated with variations in probability-net refinement-based information. Computational results and insights are presented based on flight test cases derived from the Enhanced Traffic Management System data provided by the FAA and using weather scenarios derived from the Model Output Statistics forecast data provided by the National Weather Service. 相似文献
266.
Work zones exist widely on urban arterials in the cities that are undergoing road construction or maintenance. However, the existing studies on arterial work zones are very limited, especially on the work zones at urban intersections, although they have a severe negative impact on the urban traffic system. For the first time, this study focuses on how work zones reduce intersection capacity. A type of widely observed work zone, the straddling work zone that straddles on a road segment and an intersection, is studied. A linear regression model and a multiplicative model suggested by Highway Capacity Manual are proposed respectively to determine the saturation flow rate of the signal intersection with the straddling work zone. The data of 22 straddling work zones are collected and used to evaluate the performances of the proposed models. The results display that the linear regression model outperforms the multiplicative model suggested by Highway Capacity Manual. The study also reveals that reducing approach (or exit) lanes and the mixture of motor vehicles and non‐motor vehicles (and pedestrians) can significantly decrease the capacity of the intersection with straddling work zone. Therefore, in setting a straddling work zone, workers should try to ensure that the intersection approach and exit are unobstructed and set a separation for non‐motors and pedestrians to avoid mixed traffic flow. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
267.
基于正交试验分析公路边坡稳定性影响因素 总被引:1,自引:0,他引:1
在常张高速公路试验路段边坡稳定性影响因素确定中,采用正交试验方法对坡面角、裂隙饱水系数、岩层走向和路线夹角、岩层倾角、边坡高度等主要因素对边坡稳定性的敏感性作一分析,得到弱风化页岩边坡稳定的一些初步规律,可为边坡开挖设计和加固方案优化提供重要依据。 相似文献
268.
为了得出垄茶高速沿线复合岩层岩质边坡稳定性主要影响因素及破坏模式,进行了现场调研及室内试验,得出水大大降低边坡岩体的抗劈裂强度和抗剪切强度,较天然状态下抗劈裂强度降低55.7%,岩体粘聚力下降75%内摩角下降26%,复合结构面的结构面连续性﹑结构面表面状况及结构面充填物等3个方面对边坡稳定性的影响较大,总结得出水和多层软弱结构面是影响垄茶沿线边坡稳定性的主要因素,滑移-拉裂-剪断破坏是边坡最主要破坏模式。 相似文献
269.
目前大量的沿海区域城市开始逐渐发展围海造陆工程,以创造出更多的建筑用地。目前地基处理方法中常用的是堆载预压法、复合地基处理法和真空预压法等方法。本文结合工程实例,分析真空预压抽真空阶段质量控制的重点及通病。 相似文献
270.
Applying multiple kernel learning and support vector machine for solving the multicriteria and nonlinearity problems of traffic flow prediction 下载免费PDF全文
This article proposes to develop a prediction model for traffic flow using kernel learning methods such as support vector machine (SVM) and multiple kernel learning (MKL). Traffic flow prediction is a dynamic problem owing to its complex nature of multicriteria and nonlinearity. Influential factors of traffic flow were firstly investigated; five‐point scale and entropy methods were employed to transfer the qualitative factors into quantitative ones and rank these factors, respectively. Then, SVM and MKL‐based prediction models were developed, with the influential factors and the traffic flow as the input and output variables. The prediction capability of MKL was compared with SVM through a case study. It is proved that both the SVM and MKL perform well in prediction with regard to the accuracy rate and efficiency, and MKL is more preferable with a higher accuracy rate when under proper parameters setting. Therefore, MKL can enhance the decision‐making of traffic flow prediction. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献