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991.
To improve the enterprise resource utilization and shorten the cycle of the whole project portfolio,a scheduling model based on Design Structure Matrix ( DSM) is built. By setting the project activity weight index system and calculating the activity weight for the project portfolio,the constraint relationship between project portfolio information and resource utilization,as the two dimensions of the DSM,are fully reflected in the schedule model to determine the order of these activities of project portfolio. A project portfolio example is given to illustrate the applicability and effectiveness of the schedule model. 相似文献
992.
High prices are often quoted as an obstacle to consumer purchase of organic food products. This article investigates the market performance of organic food products at different price levels and whether high price is necessarily a disadvantage for organic food products, especially with regard to generating repeat purchase. Based on analyses of panel purchase data from 2011 in Denmark, the study explores the effects of production method (organic vs. conventional) and price on consumers’ repeat purchase and cross-purchase across four product categories: red meat, chicken, milk and hard cheese. Results show that a high price is a disadvantage for generating repeat purchase of organic food products. Although organic products enjoy higher repeat purchase than conventional products overall, a high price generates less repeat purchase of organic products than a low or a medium price in all product categories; whereas in the case of conventional food products the situation is the reverse. At the same time, the cross-purchase analysis reveals that consumers who buy organic products from the high price tier are less likely to switch to other price tiers than consumers who buy low or medium price organic products (i.e. there is a spillover of high price organic food purchases to other product categories). Implications for pricing strategies for organic food products are discussed. 相似文献
993.
针对抗震结构研究了能够综合考虑结构弹塑性位移耦合作用的滞回耗能谱(简称"VH谱")。通过自编的Matlab程序,进行了大量的单自由度体系非线性时程分析,计算得到了一系列VH谱曲线,并拟合回归了4类场地的VH谱公式及其相关系数。VH谱综合考虑了结构最大弹塑性位移和结构累积滞回耗能的耦合作用,更加合理地反映结构在罕遇地震作用下的弹塑性行为,研究成果可供抗震结构基于能量性能设计或评估使用。 相似文献
994.
《国际计算机数学杂志》2012,89(8):1051-1059
A new triparametric family of three-step optimal eighth-order iterative methods free from second derivatives are proposed in this paper, to find a simple root of nonlinear equations. Convergence analysis as well as numerical experiments confirms the eighth-order convergence and asymptotic error constants. 相似文献
995.
介绍了直接饮用水对人体的危害,叙述了生活饮用水处理工艺的目的和应用特点,在二次供水设施清洗工艺流程中应注意的事项及要点,饮用水在处理前后的差异和处理后水质的标准及评价。对全面了解清洗技术在生活饮用水质中的应用具有重要意义。 相似文献
996.
Lidan Pei Zhiwei Ni Huayou Chen Zhifu Tao 《International journal of systems science》2017,48(13):2779-2793
As a new preference structure, the intuitionistic fuzzy linguistic preference relation (IFLPR) was recently introduced to efficiently deal with situations in which the membership and non-membership are represented as linguistic terms. In this paper, we study the issues of additive consistency and the derivation of the intuitionistic fuzzy weight vector of an IFLPR. First, the new concepts of order consistency, additive consistency and weak transitivity for IFLPRs are introduced, and followed by a discussion of the characterisation about additive consistent IFLPRs. Then, a parameterised transformation approach is investigated to convert the normalised intuitionistic fuzzy weight vector into additive consistent IFLPRs. After that, a linear optimisation model is established to derive the normalised intuitionistic fuzzy weights for IFLPRs, and a consistency index is defined to measure the deviation degree between an IFLPR and its additive consistent IFLPR. Furthermore, we develop an automatic iterative decision-making method to improve the IFLPRs with unacceptable additive consistency until the adjusted IFLPRs are acceptable additive consistent, and it helps the decision-maker to obtain the reasonable and reliable decision-making results. Finally, an illustrative example is provided to demonstrate the validity and applicability of the proposed method. 相似文献
997.
During heat waves, fatal overexposure to heat most often occurs at home. It is not known how factors such as building size, floor level, and different types of air conditioning (AC) contribute to excess indoor heat. We monitored indoor temperature and humidity in 36 apartments in New York City during summers 2014 and 2015 and used these values to calculate the indoor heat index (HI). We investigated the role of AC type and building‐level factors on indoor HI using multilevel regression models. Thirty‐four of 36 homes had AC. Central and ductless AC types were associated with the coolest indoor conditions; homes with window and portable AC were significantly warmer. Apartments on the top floor of a building were significantly hotter during heat advisory periods than other apartments regardless of the presence of AC. High indoor HI levels persisted in some homes for approximately 1 day following the end of the two heat advisory periods. We provide concrete evidence of higher heat levels in top floor apartments and in homes with certain types of AC. High heat levels that persist indoors after outdoor heat has subsided may present an underappreciated public health risk. 相似文献
998.
基于全装配式桁架梁组合楼盖的缩尺模型试验,采用Midas/Gen有限元软件对其进行了分析模拟,通过与试验研究结果的对比,验证了有限元分析模型的准确性。在楼盖刚性假定的基础上,对试验楼盖在楼层水平力作用下的平面内受力变形性能进行了模拟分析。研究结果表明:考虑楼盖平面内刚度与假定楼盖理想刚性两种情形下,该全装配式桁架梁组合楼盖的整体位移偏差较大,而柱端剪力偏差较小;美国规范(ASCE/SEI 41-13)评估法不适合该类楼盖的刚性性能评估;建议综合考虑楼盖整体位移与柱端剪力在考虑楼盖平面内刚度与假定楼盖理想刚性时的偏差均不超过10%作为全装配式楼盖平面内刚性性能分析评估的指标;基于该分析评估指标,全装配式桁架梁组合楼盖属于非刚性楼盖。 相似文献
999.
《Measurement》2016
This paper reports the results of our recent studies on evanescent-field photonic microcells (PMCs) made by post-processing commercial micro-structured optical fibers and by encapsulating tapered micro/nano fibers within glass capillaries. The PMCs have a wavelength/sub-wavelength scale wave-guiding core housed within a miniature hollow compartment. The housing isolates the waveguide core from external contamination and provides a robust platform for efficient evanescent field interaction with the materials filling the compartment. The techniques for fabrication are described and the applications of the PMCs for sensing temperature, gas pressure, refractive index and mechanical acceleration are discussed. 相似文献
1000.
Matteo Ottavian Pierantonio Facco Massimiliano Barolo Paolo Berzaghi Severino Segato Enrico Novelli Stefania Balzan 《Journal of food engineering》2012
This study investigated the possibility of using near-infrared spectroscopy (NIRS) for the authentication of Asiago d’allevo, a protected designation of origin cheese from northern Italy. Latent variable models applied on spectral data were developed and used to estimate several chemical properties and to classify the available dataset according to the location and management of the cheesemaking factory (lowland and alpine), the ripening age (6, 12, 18 and 36 months), the altitude of milk production (low, medium, medium–high and high), and the period of the year of the cheese production (May, July and September). The variable importance in projection index was used to identify the most informative spectral regions for discrimination. Results showed that NIR spectra can be used both to accurately estimate several chemical properties and to classify the samples according to the different experimental conditions under investigation with the same discrimination capacity provided by traditional chemical analysis. 相似文献