结合新型模糊支持向量机和证据理论的多传感器水质数据融合

在多传感器水质数据融合领域，证据理论是有效的数据融合方法之一，但基本概率分配一般不易确定，从而使数据融合能力难以有效发挥。支持向量机是统计学习理论之上的高级分类算法，具有普适性和全局优化等特点，但输出的基本概率分配有待进一步提高。提出了一种基于证据理论和新型模糊支持向量机相结合的数据融合方法，通过建立基于分类超平面距离的模糊隶属度，训练模糊支持向量机提高传统支持向量机的基本概率分配，并结合证据理论进行海河水质数据融合。通过证据理论分别结合支持向量机和模糊综合评价法与上述方法进行对比实验，经精度、平均绝对百分误差、均方根误差等指标验证，精度提高10.5%，表明所提方法是一种可靠的多传感器的水质融合方法，较其他方法具有更高的融合精度。     

Does oligopsony power matter in price support policy design? Empirical evidence from the Thai Jasmine rice market

In the oligopsony market, farmers may receive low prices and policy analysis assuming perfect competition can yield serious bias results. In this paper, we estimate oligopsony power between processors and farmers and evaluate the welfare impact of the paddy pledging program (PPP), a generous price support program in the Thai Jasmine rice market, with an imperfect competition model. We develop a model that consists of rice supply equation and derived demand equation. We then simultaneously estimate these equations using system estimation methods to recover oligopsony power parameters. Finally, we use these parameters to assess the welfare impact of the price support program. Using annual panel data running from crop marketing year 2001/2002–2015/2016 and exploiting the institutional feature of the PPP, we find strong evidence of some oligopsony power, a moderate level of oligopsony price distortion, and a negative relationship between price support and oligopsony power. We also find that the PPP is inefficient but effective in income redistribution. Moreover, the program benefits both farmers and consumers. With better policymaking decisions, the PPP can be efficient by setting a suitable support price. Therefore, our results show that in the case of the Thai Jasmine rice market, the generally accepted “wisdom” about agricultural price support policy does not necessarily hold, and price support can be designed to improve the efficiency of the market.     

A political economy perspective on horizontal FDI in a dynamic Cournot-oligopoly with endogenous entry

Entry in a homogeneous Cournot-oligopoly is excessive if and only if there is business-stealing (Amir et al., 2014). The excessive entry prediction has been derived primarily for closed economies and using a welfarist benchmark. We extend this framework and allow for (1) horizontal FDI in a multi-period setting and (2) interest group-based government behaviour. Opening the market to greenfield investments from abroad tends to aggravate the entry distortion. Moreover, market opening may reduce welfare if a more pronounced entry distortion dominates the gain in consumer surplus. Finally, a government, which places sufficiently little weight on the interests of consumers, will object to market opening, even if welfare rises.     

Residents' place image: a cluster analysis and its links to place attachment and support for tourism

While there is a plethora of studies segmenting the lucrative tourism market, limited attention has been given to identifying potential segments of local residents based on their image of the place they live in as a tourist destination. This study aims to address this gap by (a) clustering local residents of a tourist destination based on their images of that place; and (b) identifying whether those image-based resident groups share similar/different levels of place attachment and intentions toward tourism (support for tourism, intention to recommend it to others). Analysis was based on a sample of 368 residents of Eilat, Israel. The findings suggest the presence of three resident groups with different images of Eilat – called Nature Aesthete, Appreciator, and Critical – and provide support that these groups exhibit dissimilar levels of attachment and intentions/behavior toward tourism. The Appreciator (residents with the most favorable image) were reported exhibiting higher levels of place attachment, support for tourism and were more likely to recommend their place to others as a tourist destination than the Critical (residents with the least favorable image). The implications of these findings to tourism theory and practice are discussed.     

Community supported agriculture membership: The benefits of spousal involvement

Fresh vegetables originating from alternative food networks (AFNs) are an increasingly popular choice all over the world. Being part of an AFN frequently redefines consumption and participation of family members in food‐related activities. Community Supported Agriculture (CSA) is a type of AFN, providing increased access to produce in a form of risk‐sharing model between farmers and consumers, which at the same time influences organization of household resources. Thus, not only the given member of a CSA, but also his/her spousal activities in household processes should be taken in account. It is clear that entering into CSA significantly affects lifestyles and frequently requires a great deal of adaptation, possibly leading to a crisis of whether to stay within the CSA or cease membership. The objective of this study was to reveal how spouses influence CSA membership. Using an explorative design, this study has identified three emerging patterns of spousal influence: coherent, integrative and neutral/antagonistic. The spousal influence on CSA membership may represent partner activities regarding food issues but also has an effect on food preparation and culinary choices at home. Our findings suggest that membership in CSA presents challenges and thus spousal support is crucial in the long term. As a consequence, spousal influence should be examined in relation to CSA participation. Inconveniences associated with CSA membership could be avoided by providing more information about the importance of spousal support.     

The international market selection of Chinese SMEs: How institutional influence overrides psychic distance

The purpose of this research is to contribute to the ongoing debate about whether psychic distance still plays a vital role in the internationalisation of SMEs from emerging markets. Drawing on the prior research which suggests the salient impact of institutional factors on internationalisation, we investigate the role of home country institutions in international market selection. Adopting a multi-case methodology, we collected semi-structured interview data from six small and medium-sized manufacturing firms in China. Our findings suggest that while psychic distance is still important in some circumstances, both formal institutions, such as government support, and informal institutions, such as business and political guanxi, enable Chinese SMEs to choose psychically distant markets. Our findings also indicate that informal institutions interact with formal institutions to further influence SMEs’ international market selection. This research contributes to SME internationalisation studies by revealing how formal and informal institutional factors override psychic distance in influencing international market selection.     

价格支持政策对我国不同粮食作物播种面积变化的影响差异

［目的］文章评估了价格支持政策对不同粮食作物播种面积变化的平均效应与动态效应，并测度多种价格支持政策的交叉政策弹性。［方法］基于1998—2016年实施粮食价格支持政策省份面板数据，设立对照组，利用倾向得分匹配—双重差分方法（PSM DID）评估价格支持政策平均效应与动态效应，并构建粮食作物供给反应（Nerlove）模型测度价格支持政策的交叉政策弹性。［结果］（1）价格支持政策对水稻、小麦、玉米播种面积增加具有不同程度的推动作用，按大小依次为玉米>水稻>小麦，对大豆播种面积变化影响不显著； （2）价格支持政策持续时间越长，对水稻、玉米播种面积增加的推动作用越大，对小麦播种面积增加的推动作用较为稳定； （3）小麦、玉米播种面积变化主要来自自身价格支持政策，水稻播种面积变化除了受到自身价格支持政策影响外，还受到其他作物政策影响，大豆播种面积变化对玉米临储政策反应敏感，对自身价格支持政策反应不敏感。［结论］在制定粮食政策时既要区分政策及其持续性对不同粮食播种面积变化的影响差异，又要注意在同一地区实施多种粮食政策时，可能对不同作物产生交叉影响。     

Analytically comparing disaster resilience across multiple dimensions

It is important to compare the resilience of complex human systems to different types of disasters, in order to assess their inherent vulnerabilities and take appropriate actions to strengthen them. Resilient behavior can be complicated and multi-dimensional, however, and one must be able to characterize the different ways in which that resilience actually exhibits itself in practice. With this in mind, this paper discusses creating a multi-dimensional indicator for the resilience of a complex human system, and it explores an approach for visualizing and analyzing the relationships between each of the individual resilience dimensions. Because decision makers may differ on the relative contribution of the different dimensions to overall resilience, the paper further discusses the issue of weighting the different dimension values and the impacts that such a weighting scheme can have on the relative ranking of different scenarios. We illustrate the ability to characterize the complexity of multi-dimensional resilience by analyzing an empirical data set that measures the relative resilience of the New York metropolitan area to seven different natural disasters between 2010 and 2012.     

Enhanced network effects and stochastic modelling in generation expansion planning: Insights from an insular power system

Electricity generation capacity expansion is driven by both economic and socio-political realities. Policy makers determine public infrastructural decisions, such as climate and renewable targets, and transmission infrastructure, and the optimal generation capacity expansion follows. Policy makers therefore require planning models that can determine the optimal generation capacity mix in the long run under various scenarios, including policy choices. This work presents a planning model based on linearised alternating current optimal power flow which determines optimal generation capacity expansion and operation, in a least-cost manner, given global and local technical constraints, as well as policy decisions. We apply the model to a test case of the island of Ireland, which has two weakly interconnected systems, high renewable generation targets and low storage and interconnection. We determine the optimal generation expansion and operation out to 2030 considering the effects of increased multi-area interconnection, existing fossil fuel generation phase-out and increased renewable generation targets and carbon prices. Our results find that costs and emissions are driven primarily by the decommissioning of old inefficient generation units. High renewable targets, on the other hand, render increased carbon prices relatively ineffective in reducing system emissions. Furthermore, high renewable generation targets crowd out low-carbon power generation options such as carbon capture and storage (CCS). The strategic north-south interconnection has little effect on renewable energy source installations required to achieve renewable power generation targets but does impact on security of supply and the congestion level across the island.