32 resultados para Multi-criteria decision analysis (MCDA)

em Chinese Academy of Sciences Institutional Repositories Grid Portal


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A set of scaling criteria of a polymer flooding reservoir is derived from the governing equations, which involve gravity and capillary force, compressibility of water, oil, and rock, non-Newtonian behavior of the polymer solution, absorption, dispersion, and diffusion, etc. A numerical approach to quantify the dominance degree of each dimensionless parameter is proposed. With this approach, the sensitivity factor of each dimensionless parameter is evaluated. The results show that in polymer flooding, the order of the sensitivity factor ranges from 10(-5) to 10(0) and the dominant dimensionless parameters are generally the ratio of the oil permeability under the condition of the irreducible water saturation to water permeability under the condition of residual oil saturation, density, and viscosity ratios between water and oil, the reduced initial oleic phase saturation and the shear rate exponent of the polymer solution. It is also revealed that the dominant dimensionless parameters may be different from case to case. The effect of some physical variables, such as oil viscosity, injection rate, and permeability, on the dominance degree of the dimensionless parameters is analyzed and the dominant ones are determined for different cases.

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水库建设方案的评价,涉及投入和效益两方面。投入包括资金和工期等,称为“输入”:效益包括工农业用水增加、防洪能力强增等。称为“输出”。分析这种多输入,多输出的系统,应用数据包络分析方法是非常有效的。

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质子激发X射线荧光(proton induced X-ray emission,PIXE)技术是一种高灵敏度、非破坏性、多元素定量测定的分析方法。采用外束PIXE技术对内蒙古地区和博山出土的一批古代玻璃的化学成分进行了定量测定。结果表明:内蒙古地区出土的玻璃中,西周时期的玻璃珠是含有少量K2O和CaO助熔剂的釉砂,其主要成分为SiO2;汉代的玻璃珠属于PbO—SiO2玻璃;多数元代的玻璃制品和部分北魏时期的玻璃珠属于K2O—CaO—SiO2玻璃。博山出土的元末明初的玻璃基本为KzO-CaO—SiO2系玻璃

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草地退化不仅仅是今天中国才发生的事情。历史上曾经发生“黑尘暴”的美国North Dakota州,现在仍然有62.7%土地被用作耕作,林地所占面积仅仅占1%。私有制和种植业较畜牧业的高的利润率,是该州种植业比重高于畜牧业的重要原因。草原保护项目(CRP)得到了美国政府财政的大力支持, 在North Dakota州采用了以草地恢复为主的措施。美国发达的教育体系带来的高流动率,使得North Dakota州自30年代后居住人口稳定在60-70万成为可能,从而避免了我国出现的草原地区不断增加的人口压力。由此可见:草地作为重要的自然资源,不可能完全保护起来;没有其他配套措施,私有制可能会带来新一轮垦殖;草地畜牧业仍然是畜牧业的重要组成部分,畜牧业发展需要结合种植业尤其需要与饲料生产相结合。 依据生态系统服务的理念,首次发展了生态系统服务指数(ESI),试图通过对生态系统服务功能的综合考虑,提出科学的适宜放牧率的评价方法。本文利用美国北达科他州立大学中部草原研究站17年长期放牧试验数据,选取植物多样性Shannon-Wiener指数、地上净初级生产力、土壤表层含水量和单位面积家畜增重等四个指标,通过对不同指标分别赋予不同的权重,计算不同管理目标下ESI及其稳定性,并对单目标管理与多目标管理进行了比较研究。结果表明,对于北美混合普列里(Prairie)草地,围封不利用或建立自然保护区,虽然生态系统比较稳定,但既不能有效的提高植物多样性、初级生产力和土壤水分含量等生态功能,又没有畜产品产出;而在重牧或极重牧处理下虽然获得了较大的畜产品生产,但导致了草地生态系统的退化和较大的系统不稳定性。因此,这两种管理方式在实践中都是不可取的。应用生态系统服务指数综合考虑,认为应该权衡各项生态功能和生产功能,此时轻牧或中牧是最适宜的。因此,ESI的建立避免了单项指标的评价偏差,使得适宜放牧率的确定更加合理。 利用前面构建的多目标权重评价体系,结合内蒙古草原生态系统定位站放牧试验样地的数据,探讨了锡林郭勒盟定位站附近的适宜放牧率为2.67羊/ha,低于单目标条件下的每公顷绵羊4羊/ha。同时在经济学和生态系统系统服务理论的基础上,依据谢高地等人(2001年)的研究,并提出了环境税和生态补偿的标准,分别是每公顷15元和90元。

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Magneto-transport measurements have been carried out on a Si heavily delta-doped In0.52Al0.48As/In(0.53)G(0.47)As single quantum well in the temperature range between 1.5 and 60 K under magnetic field up to 10 T. We studied the Shubnikov-de Haas(SdH) effect and the Hall effect for the In0.52Al0.48As/In(0.53)G(0.47)As single quantum well occupied by two subbands, and have obtained the electron concentration, mobility, effective mass and energy levels respectively. The electron concentrations of the two subbands derived from mobility spectrum combined with multi-carrier fitting analysis are well consistent with the result from the SdH oscillation. From fast Fourier transform analysis for d(2)rho/dB(2)-1/B, it is observed that there is a frequency of f(1)-f(2) insensitive to the temperature, besides the frequencies f(1), f(2) for the two subbands and the frequency doubling 2f(1), both dependent on the temperature. This is because That the electrons occupying the two different subbands almost have the same effective mass in the quantum well and the magneto-intersubband scattering between the two subbands is strong.

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The characteristic Ll, Lα, Lβ and Lγx-rays of Au and energy shifts produced by 20–50MeV 16O5+ beams on a thick Au ilm are measured with a Si (Li) detector. Cross-section ratios of σ(Ll)/σ(Lα), σ(Lβ)/σ(Lα) andσ(Lγ)/σ(Lα) versus O5+ energy show that consistent calculations yield considerably better agreements. Energy shifts Ll, Lα, Lβ and Lγ x-rays of Au target increase with more incidence energy. The main application for these measurements is multi-element trace analysis through particle induced x-ray emission.

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This study attempts to model alpine tundra vegetation dynamics in a tundra region in the Qinghai Province of China in response to global warming. We used Raster-based cellular automata and a Geographic Information System to study the spatial and temporal vegetation dynamics. The cellular automata model is implemented with IDRISI's Multi-Criteria Evaluation functionality to simulate the spatial patterns of vegetation change assuming certain scenarios of global mean temperature increase over time. The Vegetation Dynamic Simulation Model calculates a probability surface for each vegetation type, and then combines all vegetation types into a composite map, determined by the maximum likelihood that each vegetation type should distribute to each raster unit. With scenarios of global temperature increase of I to 3 degrees C, the vegetation types such as Dry Kobresia Meadow and Dry Potentilla Shrub that are adapted to warm and dry conditions tend to become more dominant in the study area.

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空间飞行器模拟件的设计是一个具有约束的多目标多准则优化问题。本文在建立空间飞行器模拟件参数优化的数学模型的基础上,将模糊多目标决策理论用于飞行器模拟件的结构参数优化,提出了一种新的模糊评价指数。结构参数优化的结果已经用于某试验系统。

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Proven by the petroleum exploration activities, the karsts-fissure reservoir in carbonate rocks is significant to find out the large scale oil & gas field. They are made up of the four reservoir types: karsts-cave, karsts-crack, crack-cave and fracture-pore-cave. Each reservoir space and each reservoir bed has different features of reservoir heterogeneity and small scale of pore-crack-cave. The fracture-cave reservoir in carbonate rocks is characteristic by multi-types and long oiliness well. The reservoir shape is controlled by the irregular pore-crack-cave. The development level of fracture and karst-cave is the key element of hydrocarbon enriching, high productivity and stable production. However, most of Carbonate formation are buried deeply and the signal-ration-noise of seismic reflection are very low. It is reason why the fracture-cave reservoir are difficult to be predicted effectively. In terms of surveyed and studied lots of the former research outcome, The author applied the methods of synthetical reservoir geophysical prediction from two ways including macrosopic and microcomic technics in terms of the reservoir-cap condition, geophysics and geology feature and difficulty of prediction in carbonate rocks. It is guiden by the new ideas of stratigraphy, sedimentology, sedimentography, reservoir geology and karst geology. The geophysics technology is key technics. In aspects of macroscopic studies, starting off the three efficiencies of controlling the reservoir distribution including sedimental facies, karst and fracture, by means of comprehensive utilization of geology, geophysics, boring well and well log, the study of reservoir features and karst inside story are developed in terms of data of individual well and multiple well. Through establishing the carbonate deposition model, karstic model and fracture model, the macro-distribution laws of carbonatite are carried out by the study of coherence analysis, seismic reflection feature analysis and palaeotectonics analysis. In aspects of microcosmic studies, starting off analysis in reservoir geophysical response feature of fracture and karst-cave model according to guidance of the macroscopic geological model in carbonate reservoir, the methods of the carbonate reservoir prediction are developed by comprehensively utilization of seismic multi-attribution intersection analysis, seismic inversion restricted by log, seismic discontinuity analysis, seimic spectrum attenuation gradient, moniliform reflection feature analysis and multiparameter karst reservoir appraisement.Through application of carbonate reservoir synthetical geophysics prediction, the author r successfully develops the beneficial reservoir distribution province in Ordovician of Katake block 1in middle Tarim basin. The fracture-cave reservoir distributions are delineated. The prospect direction and favorable aims are demonstrated. There are a set of carbonate reservoir prediction methods in middle Tarim basin. It is the favorable basic technique in predicting reservoir of the Ordovician carbonate in middle Tarim. Proven by exploration drilling, the favorable region of moniliform reflection fracture and pore-cave and cave-fracture in lower-middle Ordovician are coincidence with the region of hydrocarbon show. It’s indicated that the reservoir prediction methods described in the study of Ordovician carbonate formation are feasible practicably.

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Application of long-term exploration for oil and gas shows that the reservoir technology of prediction is one of the most valuable methods. Quantitative analysis of reservoir complexity is also a key technology of reservoir prediction. The current reservoir technologies of prediction are based on the linear assumption of various physical relationships. Therefore, these technologies cannot handle complex reservoirs with thin sands, high heterogeneities in lithological composition and strong varieties in petrophysical properties. Based on the above-mentioned complex reservoir, this paper conducts a series of researches. Both the comprehending and the quantitative analysis of reservoir heterogeneities have been implemented using statistical and non-linear theories of geophysics. At the beginning, the research of random media theories about reservoir heterogeneities was researched in this thesis. One-dimensional (1-D) and two-dimensional (2-D) random medium models were constructed. The autocorrelation lengths of random medium described the mean scale of heterogeneous anomaly in horizontal and deep directions, respectively. The characteristic of random medium models were analyzed. We also studied the corresponding relationship between the reservoir heterogeneities and autocorrelation lengths. Because heterogeneity of reservoir has fractal nature, we described heterogeneity of reservoir by fractal theory based on analyzing of the one-dimensional (1-D) and two-dimensional (2-D) random medium models. We simulated two-dimensional (2-D) random fluctuation medium in different parameters. From the simulated results, we can know that the main features of the two-dimensional (2-D) random medium mode. With autocorrelation lengths becoming larger, scales of heterogeneous geologic bodies in models became bigger. In addition, with the autocorrelation lengths becoming very larger, the layer characteristic of the models is very obvious. It would be difficult to identify sandstone such as gritstone, clay, dense sandstone and gas sandstone and so on in the reservoir with traditional impedance inversion. According to the obvious difference between different lithologic and petrophysical impedance, we studied multi-scale reservoir heterogeneities and developed new technologies. The distribution features of reservoir lithological and petrophysical heterogeneities along vertical and transverse directions were described quantitatively using multi-scale power spectrum and heterogeneity spectrum methods in this paper. Power spectrum (P spectrum) describes the manner of the vertical distribution of reservoir lithologic and petrophysical parameters and the large-scale and small-scale heterogeneities along vertical direction. Heterogeneity spectrum (H spectrum) describes the structure of the reservoir lithologic and petrophysical parameters mainly, that is to say, proportional composition of each lithological and petrophysical heterogeneities are calculated in this formation. The method is more reasonable to describe the degree of transverse multi-scale heterogeneities in reservoir lithological and petrophysical parameters. Using information of sonic logs in Sulige oil field, two spectral methods have been applied to the oil field, and good analytic results have been obtained. In order to contrast the former researches, the last part is the multi-scale character analysis of reservoir based on the transmission character of wave using the wavelet transform. We discussed the method applied to demarcate sequence stratigraphy and also analyzed the reservoir interlayer heterogeneity.

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This dissertation systematically depicted and improved the application of Independent Component Analysis (ICA) to Functional Magnetic Resonance Imaging (fMRI), following the logic of verification, improvement, extension, and application. The concept of “reproducibility” was the philosophy throughout its four concluded studies. In the “verification” study, ICA was applied to the resting-state fMRI data, verified the resultant components with reproducibility, and examined the consistency of the results from ICA and traditional “seed voxel” method. At the meantime, the limitation of ICA application on fMRI data analysis was presented. In the “improvement” study, an improved ICA algorithm based on reproducibility, RAICAR, was developed to aid some of the limitations of ICA application. RAICAR was able to rank ICA components by reproducibility, determine the number of reliable components, and obtain more stable results. RAICAR provided useful tools for validation and interpretation of ICA results. In the “extension” study, RAICAR as well as the concept of “reproducibility” was extended to multi-subject ICA analysis, and gRAICAR algorithm was developed. gRAICAR allows some variation across subjects, examining common components among subjects. gRAICAR is also capable to detect potential subject grouping on some components. It is a new way for exploratory group analysis on fMRI. In the “application” study, two newly developed methods, RAICAR and gRAICAR, were used to investigate the effect of early music training on the brain mechanism of memory and learning. The results showed brain mechanism difference in memory retrieval and learning process between two groups of subjects. This study also verified the usefulness and importance of the new methods.

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In current days, many companies have carried out their branding strategies, because strong brand usually provides confidence and reduce risks to its consumers. No matter what a brand is based on tangible products or services, it will possess the common attributes of this category, and it also has its unique attributes. Brand attribute is defined as descriptive features, which are intrinsic characteristics, values or benefits endowed by users of the product or service (Keller, 1993; Romaniuk, 2003). The researches on models of brand multi-attributes are one of the most studied areas of consumer psychology (Werbel, 1978), and attribute weight is one of its key pursuits. Marketing practitioners also paid much attention to evaluations of attributes. Because those evaluations are relevant to the competitiveness and the strategies of promotion and new product development of the company (Green & Krieger, 1995). Then, how brand attributes correlate with weight judgments? And what features the attribute judgment reaction? Especially, what will feature the attribute weight judgment process of consumer who is facing the homogeneity of brands? Enlightened by the lexical hypothesis of researches on personality traits of psychology, this study choose search engine brands as the subject and adopt reaction time, which has been introduced into multi-attributes decision making by many researchers. Researches on independence of affect and cognition and on primacy of affect have cued us that we can categorize brand attributes into informative and affective ones. Meanwhile, Park has gone further to differentiate representative and experiential with functional attributes. This classification reflects the trend of emotion-branding and brand-consumer relationship. Three parts compose the research: the survey to collect attribute words, experiment one on affective primacy and experiment two on correlation between weight judgment and reaction. The results are as follow: In experiment one, we found: (1) affect words are not rated significantly from cognitive attributes, but affect words are responded faster than cognitive ones; (2) subjects comprehend and respond in different ways to functional attribute words and to representative and experiential words. In experiment two, we fund: (1) a significant negative correlation between attributes weight judgment and reaction time; (2) affective attributes will cause faster reaction than cognitive ones; (3) the reaction time difference between functional and representative or experiential attribute is significant, but there is no different between representative and experiential. In sum, we conclude that: (1): In word comprehension and weight judgment, we observed the affective primacy, even when the affect stimulus is presented as meaningful words. (2): The negative correlation between weight judgment and reaction time suggest us that the more important of attribute, the quicker of the reaction. (3): The difference on reaction time of functional, representative and experiential reflects the trend of emotional branding.

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The quality of advertising copy is an important component of advertising service. An advertising system with only copy design and production but without evaluation is imperfect. Establishing an evaluation system of television advertising copy is the principal purpose of the present work. In terms of consumer behavior, the work focused on consumers' evaluation-in-general of T commercials. The research consisted of three subprograms. The first subprogrom was associated with the basic factors in the evaluation of television advertising copy. The second one was related to the relative importance of those basic factors. The last one was related to the way in which the consumers' synthetic evaluation of copy under multidimensions. These subprogram composed the evaluation system of television advertising copy. In the study of the first subprogram, by the use of a variaty of "multistage evaluation scale", a survey into consumers' evaluation-in-general of television ads was made, which obtained five factors, namely, credibility, attractiveness, suitability, cognition and affect impact, through factor analysis (Cum.Pct. = 56.2%, α = 0.84). The study of second subprogram acquired their relative weights by a popular method of weight in the area of decision analysis, the result was as followings: credibility-0.27, attractiveness-0.24, suitability-0.18, affect impact-0.16, cognition-0.15; and fanally, under the condition of quasi-experiment, the third studyestablished a mathematical model of the synthetic evaluation of television ad copy, which was expressed as O = ΣF * W, through a "synthetical" method of multidimensional decision making.

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Residual stress and its gradient through the thickness are among the most important properties of as-deposited films. Recently, a new mechanism based on a revised Thomas-Fermi-Dirac (TFD) model was proposed for the origin of intrinsic stress in solid film