首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 93 毫秒
1.
为了更好地保护三江平原湿地生态系统,应用条件价值评估法(CVM)这一当前国际上流行的生态系统经济价值评价方法,对三江平原湿地的非使用价值进行评价.研究中采用实地调研的方式,进行支付意愿问卷调查,共发放支付卡式CVM问卷552份,回收有效问卷513份.得出三江平原湿地2007年人均支付意愿为71.66元/年.通过对问卷数据的描述性统计,得到支付意愿的分布情况和在各单一因素影响下的变化规律.用主成分分析简化影响因素,运用有序多分类Logit模型,得到在所有影响因素中,个人平均年收入、个人受教育程度以及个人环保态度是影响受访者对三江平原湿地非使用价值支付意愿的主要因素.研究结论使得三江平原湿地开发和保护价值比较成为可能,为政府制定相关政策提供理论基础与科学依据.  相似文献   

2.
水价是调节水资源供给与需求的重要手段之一,而农民的支付能力和支付意愿是干旱区水价改革的关键点.为此,选取典型干旱区民勤为例,采用该地区的实际调查数据,利用多元排序选择模型对民勤绿洲灌区农民支付的实际灌溉水价和意愿灌溉水价及其影响因素进行研究.结果表明:1)农民支付的不同农作物平均实际灌溉水价为每公顷2700元,占其平均净收益的56.2%. 2)农民的意愿灌溉水价为每公顷75元-675元,占农业平均净收益的比重为1.2%-11.1%. 3)影响农民意愿灌溉水价在统计学上显著的因素有:受访者的年龄、文化程度,家庭劳动力的平均文化程度,家庭耕地的集中程度,家庭的年人均纯收入、农业收入占总收入的比重,受访者对生态环境保护知识的了解程度、对生态保护紧迫性的认知度,水资源管理政策满意度、节水技术支持.农民实际支付的不同农作物平均灌溉水价高于水利部发展研究中心得出的水费占农业净收益的比重10%-20%的合理范围这一结论,而农民的意愿灌溉水价远低于这一适宜范围,最后,提出了提升农民意愿灌溉水价的四点建议.  相似文献   

3.
本文以辽河流域作为研究对象,通过实地走访和调研辽河流域的源头一福德店与入海口一盘锦市,采用条件价值法分别对辽河流域居民的生态受偿意愿(WTA)及生态支付意愿(WTP)进行测算,着重探讨WTP与WTA的差异性,分析引起这种差异的社会经济影响因素。本文采用斯皮尔曼法进行相关性分析,发现WTP与WTA的差异性存在着如下特征:一是从WTP与WTA的概率分布来看,二者存在着较大差异;二是从WTP与WTA各自的影响因素来看,WTP受收入的影响而WTA不受收入的影响,收入效应很好地解释了WTA超过WTP的原因;三是WTA与WTP的比值在经验范围以内为2.357;四是引起WTP与WTA差异的社会经济因素有性别、职业和流域生态补偿政策对受访者的影响程度。而对上述特征进行分析后发现惩罚效应和模糊性也是导致辽河流域居民支付意愿和受偿意愿差异的原因。  相似文献   

4.
采用三江平原湿地调查问卷结果作为原始数据,探讨了灰建模方法在条件价值法数据处理中的应用.在对问卷数据进行聚类分析的基础上,采用传统的GM(1,1)模型,得到了合理有效的灰色模型,改进了条件价值法数据建模中仅将支付与抗议支付作为两个基本变量的模型,得出了多分类模型.  相似文献   

5.
为了更好地发挥中巴地球资源卫星的社会效益,同时为中巴地球资源卫星的使用和管理部门提供决策参考依据,应用条件价值法(CVM),采用支付意愿问卷调查的方式,通过数据统计和回归分析,对中巴地球资源卫星的社会效益进行定量评价,得到了影响中巴地球资源卫星社会效益支付意愿的主要因素.共发放问卷2330份,收回有效问卷2285份,通过对问卷数据的描述性统计,得到支付意愿的分布情况和在各单一因素影响下的变化规律.用主成分分析简化影响因素,运用二元Logit回归模型和Tobit模型,得到在所有的影响因素中,对中巴地球资源卫星的重视性、个人平均年收入是影响被调查者对中巴地球资源卫星社会效益的支付意愿的主要因素.研究结论使得中巴地球资源卫星的收益和成本的比较成为可能,为政府制定相关政策提供理论基础.  相似文献   

6.
对居民家庭进行抽样调查时,常常出于隐私或缺乏专业知识背景的原因,使得居民对被调查的经济变量不愿或无法给出准确值,从而影响调查数据的质量.在此情况下,国外知名的调查(如,美国的消费金融调查)会将调查变量的取值范围划分成一系列连续的、长度不等的区间,请受访者选择,以此来消除受访者的戒备和疑虑心理,收集家庭的经济变量的信息,但这种区间的划分是一种经验划分.从降低数据分析误差的角度提出了一种优化区间长度的设计思路,利用遗传算法给出了问题求解的方法,最后通过一个实际例子加以说明.方法对提高调查变量的数据质量颇有帮助.  相似文献   

7.
运输问题是一类特殊的线性规划问题,通常用特殊的单纯形法—运输单纯形法(也叫表上作业法)进行求解,其最优性条件为所有非基变量的检验数大于等于零.针对实际算例中出现的某个非基变量的检验数小于零,却已经达到最优的情况,从可行下降方向的角度进行了探讨.结论表明:一般情况下非基变量的检验数大于等于零仅是运输问题最优解的充分条件;而问题非退化时,该判别条件成为充要条件.  相似文献   

8.
通过SERVPERF服务质量评价方法和逐步向前回归对所获取的针对中科院后勤服务质量评价的问卷调查数据进行了实证研究.首先根据两种方法,设计问卷量表进行问卷调查,并回收问卷,对数据进行处理和信度检验.运用SERVPERF和IPA四象限方法相结合,对22项普遍关注的后勤服务问题进行分析评价.通过增加控制变量的逐步向前回归方法对影响后勤质量的因素进行了进一步分析.汇总两部分得到的结论,进行对比分析发现,尽管受访者对中科院后勤服务质量普遍比较满意,但通过深入分析仍有较大的改进空间.现阶段,提高食堂相关的服务质量将有助于中科院后勤服务质量的较大提升;校园各类设施和人员服务也是受访者普遍关注的指标;校园生活的便利性也是影响受访者评价科研院所后勤服务质量的重要组成部分.  相似文献   

9.
弹性地基无限长梁动力问题的一般解   总被引:7,自引:1,他引:6  
本文从Euler-Bernoulli梁出发,对弹性地基采用Winkler假定,建立了问题的数学模型.然后对空间变量和时间变量分别进行Fourier变换和Laplace变换,利用逆变换褶积积分,得到了弹性地基无限长梁一般动力问题的解析解.最后对自由振动,脉冲激励和运动载荷情况分别进行了讨论.  相似文献   

10.
调节变量(moderator)辨析:类型、表述和识别   总被引:2,自引:0,他引:2  
本文扼要阐述了调节变量在社会科学研究中的重要意义,对调节变量的分类、表述、识别检验方法进行了归纳和讨论,并就研究中应注意的有关问题进行了总结.  相似文献   

11.
This is a summary of the author’s PhD thesis. The thesis, written in English, was defended on 6 March 2006, and was supervised by Rik Van Landeghem and Claude Van Mechelen. A copy is available from the author upon request. This PhD thesis focuses on (cost-)efficient quality control for multistage production processes, a major issue to manufacturers. Subjecting a larger product fraction to inspection, or tightening the acceptance limits, will normally lead to a higher product quality, but will also result in higher costs of inspection, scrap and rework. Quantifying this trade-off and thus establishing ways of finding an economic optimum is at the heart of this research. Thereto, a metaheuristic solution approach, consisting of an evolutionary algorithm combined with simulation, is presented and validated.   相似文献   

12.
The increasing consideration of behavioral aspects in operations management models has prompted greater use of choice-based conjoint (CBC) studies in operations research. Such studies can elicit consumers’ willingness to pay (WTP), a core input for many optimization models. However, optimization models can yield valid results only if consumers’ WTP is estimated accurately. A simulation study and two field studies show that extreme response behavior in CBC studies, such that consumers always or never choose the no-purchase option, harms the validity of WTP estimates. Reporting the share of consumers who always and never select the no-purchase option allows for detecting extreme response behavior. This study suggests an individually adapted design that avoids extreme response behavior and thus significantly improves WTP estimation accuracy.  相似文献   

13.
二分选择模型在滨海旅游经济价值评价中的应用   总被引:1,自引:0,他引:1  
本文以大连滨海旅游资源为例,采用二分选择模型条件评价法(CVM)评价海水和沙滩质量改善的经济价值,探索滨海旅游资源生态补偿的价值。研究发现采用Logit二分选择模型估算旅游者意愿支付(WTP)比采用Probit模型更适合滨海旅游资源经济价值评价;在计算WTP的均值解时,采用线性效用差函数更为简单实用。将该方法用于大连旅游景区海水和沙滩质量价值评价的研究,结果表明:采用Logit和Probit模型能够得到一致的WTP;文中采用单解释变量模型可以反应多个解释变量模型的计算结果;测算得到海水沙滩质量改善的非使用价值为215元/人,进而对旅游或环境资源的保护和可持续利用可以有更明确的定量认识。这种经济价值研究方法与过程对探索滨海旅游资源生态补偿的定性研究具有重要意义。  相似文献   

14.
In a highly competitive environment, a product's commercial success depends increasingly more upon the ability to satisfy consumers' preferences that are highly diversified. Since a product typically comprises a host of technological attributes, its market value incorporates all of the individual values of technological attributes. If the willingness-to-pay (WTP) for individual quality attributes of a product is known, one can conjecture the overall WTP or the imputed market price for the product. The market price listed by the producer has to be equal to or lower than this WTP for the commercial survival of the product. In this paper, we propose a methodology for estimating the value of individual product characteristics and thus the overall WTP of the product with DEA. Our methodology is based on a model derived from consumer demand theory on the one hand, and the recent developments in DEA on the other hand. The paper also presents a real case study for the mobile phone market, which is characterized by its high speed of innovation. On the theoretical side, we expect our framework to provide a possibility of combining DEA and consumer demand theory. We also expect that the empirical application will shed some light on the nature of the process of product differentiation based on consumers' valuation.  相似文献   

15.
In this paper, cooperative advertising in a manufacturer–retailer supply chain is studied. Advertising can enhance willingness to pay (WTP) of customers. This trade-off between the benefits of increasing WTP of customers and the advertising expenditure is a key to understanding the retailers optimal advertising decision. On the other hand, it is interesting to understand in which condition supporting the retailer for his advertising expenditure is beneficial for the manufacturer. In this study, in order to capture pricing and advertising strategies of the channel member, three non-cooperative games including Nash, Stackelberg retailer and Stackelberg manufacturer game-theoretic models are established. In spite of the related studies which restrict price in order to prevent negative demand, the proposed model allows channel members to increase their prices by enhancing WTP of customers. In this study, contrary to similar additive form demand functions applied in the co-op ad literature which limits their studies for cases that profit function is concave with respect to variables, optimal prices and advertising strategies are obtained for all the solution space. Surprisingly for the very high values of the advertising effect coefficient, a finite optimal advertising expenditure is achieved.  相似文献   

16.
ABSTRACT

We show that willingness to accept (WTA) and willingness to pay (WTP) are particular cases of quasideviation means. Applying this fact we characterize some properties of WTA and WTP related to the experimentally observed disparity between them.  相似文献   

17.
The kernel‐based statistical semantic topic model is introduced for comprehending three species of internationally important Ramsar wetland documents describing the Lashi Lake wetland in the Yunnan Province, the Yancheng wetland in the Jiangsu Province, and the Zoige wetland in the Sichuan Province of China. Latent Dirichlet allocation (LDA) features are used to represent the semantic components of wetland documents. Kernel principal component analysis (KPCA) maps the topic components to the kernel space to attain the low dimensional principal components. Support vector machines (SVMs) are used to comprehend the semantic distribution of distinct wetland documents in the kernel space. The LDA+KPCA+SVM algorithm reaches 77.0% training and 75.9% test accuracy and 0.902 training and 0.840 test mean average precision scores in the application of comprehending the wetland documents, respectively. The performance of the proposed kernel‐based model is superior to the traditional models of LDA+SVM and LDA+PCA+SVM.  相似文献   

18.
A single inspection facility is capable of multiple inspection tasks. This facility could be used for detecting out-of-specification production stages in multistage production systems. The purpose is to schedule the inspection over the different production stages so as to minimize the fraction of nonconforming items produced. A heuristic solution is proposed. The schedule is based on a relaxation of the origical integer nonlinear scheduling problem. The relaxed problem provides upper bound and optimal sharing of the inspection efforts. Alternative cyclic schedules are then generated, shrunken and evaluated. The procedure performance is examined and further extensions are discussed.  相似文献   

19.
《Journal of Complexity》1999,15(3):402-447
We study the ε-approximation of linear multivariate problems defined over weighted tensor product Hilbert spaces of functions f of d variables. A class of weighted tensor product (WTP) algorithms is defined which depends on a number of parameters. Two classes of permissible information are studied. Λall consists of all linear functionals while Λstd consists of evaluations of f or its derivatives. We show that these multivariate problems are sometimes tractable even with a worst-case assurance. We study problem tractability by investigating when a WTP algorithm is a polynomial-time algorithm, that is, when the minimal number of information evaluations is a polynomial in 1/ε and d. For Λall we construct an optimal WTP algorithm and provide a necessary and sufficient condition for tractability in terms of the sequence of weights and the sequence of singular values for d=1. ForΛstd we obtain a weaker result by constructing a WTP algorithm which is optimal only for some weight sequences.  相似文献   

20.
This paper develops an integrated model of production lot-sizing, maintenance and quality for considering the possibilities of inspection errors, preventive maintenance (PM) errors and minimal repairs for an imperfect production system with increasing hazard rates. In this study, a PM activity is imperfect in that a production system cannot be recovered as good as new and might cause the production system to shift to the out-of-control state with a certain probability. Numerical analyses are used to simulate the effect of changes in various parameters on the optimal solution for which the time that the process remains in the in-control state is assumed to follow a Weibull distribution. In addition, we investigate the effects of inspection errors and PM errors on the minimum total cost of the optimal inspection interval, inspection frequency and production quantity.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号