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31.
胡强 《价值工程》2021,40(2):143-145
当前我国已经将决战脱贫攻坚、决胜全面建成小康社会作为主要的战略目标,为了实现这一目标,实现脱贫攻坚,电力保障是一个非常重要的因素。近年来我国全面推进农网改造升级工程。农网改造工程的接地施工质量的重要性毋庸置疑,但是农网改造工程的特殊性又使得接地质量的判断变得不好把握,本文从农网改造工程接地质量现状、防控措施等方面进行探讨。  相似文献   
32.
This paper contributes to the nascent literature on nowcasting and forecasting GDP in emerging market economies using big data methods. This is done by analyzing the usefulness of various dimension-reduction, machine learning and shrinkage methods, including sparse principal component analysis (SPCA), the elastic net, the least absolute shrinkage operator, and least angle regression when constructing predictions using latent global macroeconomic and financial factors (diffusion indexes) in a dynamic factor model (DFM). We also utilize a judgmental dimension-reduction method called the Bloomberg Relevance Index (BRI), which is an index that assigns a measure of importance to each variable in a dataset depending on the variable’s usage by market participants. Our empirical analysis shows that, when specified using dimension-reduction methods (particularly BRI and SPCA), DFMs yield superior predictions relative to both benchmark linear econometric models and simple DFMs. Moreover, global financial and macroeconomic (business cycle) diffusion indexes constructed using targeted predictors are found to be important in four of the five emerging market economies that we study (Brazil, Mexico, South Africa, and Turkey). These findings point to the importance of spillover effects across emerging market economies, and underscore the significance of characterizing such linkages parsimoniously when utilizing high-dimensional global datasets.  相似文献   
33.
段晓亮  鲁会军 《价值工程》2015,(18):146-147
采用TAW-2000D微机控制电液伺服岩石三轴试验机和SDAES型数字声发射仪组成的动态测试系统,对云南大红山铜矿白云岩进行了单轴压缩条件下的声发射试验,研究岩石在峰值应力前后声发射特性。试验结果表明:加载早期就有声发射活动,岩样在试验接近峰值强度时单位时间内的应力增长速度减小、声发射事件率出现明显下降,即出现相对平静期,峰值强度后的声发射现象仍然明显。  相似文献   
34.
针对不完备信息系统条件下的辐射源威胁等级判定问题,提出了一种基于改进容差关系粗糙集(ITR-RS)的不完备信息系统辐射源威胁等级判定方法。该方法将粗糙集中的不完备信息系统理论引入辐射源威胁等级判定中,并构建一套完备的决策规则提取模型。此外,利用辨识矩阵实现对属性的约简,在降低系统所需处理数据量的同时,提高了算法的实时性;在容差关系粗糙集的基础上,提出一种改进的容差关系,在属性主、客权重相结合的基础上引入阈值来划分加权阈值容差类,得到更为合理、准确的决策规则。仿真试验及分析表明,与经典RS算法相比,所提算法的威胁等级判定正确率提高了23%,可用于信息系统不完备条件下的辐射源威胁等级判定。  相似文献   
35.
In a bid to reduce greenhouse gas emissions, several countries worldwide are implementing policies to promote electric vehicles (EVs). However, contrary to expectations, the diffusion speed of EVs has been rather slow in South Korea. This study analyzes consumer preferences for the technological and environmental attributes of EVs and derives policy and environmental implications to promote market diffusion of EVs in South Korea. We conduct a choice‐based conjoint survey of 1,008 consumers in South Korea and estimate the consumer utility function using a mixed logit model considering consumer heterogeneity. Based on the consumer utility function, we analyze consumers' willingness‐to‐pay (WTP) for EV attributes such as driving range, charging method, charging time, autonomous driving function, carbon dioxide (CO2) reduction rate, and purchase price. The results indicate that the current low acceptance of EVs is due to their relatively high price and lack of a battery charging technology that satisfies consumers' expectations of the charging method and time. One interesting finding is that Korean consumers have a relatively higher WTP for the CO2 reduction rate of EVs than consumers in other countries; however, they do not consider CO2 reduction over other technological attributes when choosing EVs. This implies that the rate of CO2 reduction of EVs is not an important factor for South Korean consumers when buying EVs. We also calculate the effect of CO2 reduction with the market penetration of EVs and find that CO2 reduction through the diffusion of EVs depends on the country's electricity generation mix.  相似文献   
36.
This article deals with a newsvendor inventory model in light of green product marketing of corporate social responsible firms. In this model, comparison between green and non green marketing is analyzed including subsidy and tax implementation by Government where the Government offers higher subsidy and lower tax to the green producer unlike the lower subsidy and higher tax to the non green producer. There is also price contest between green and non green producer as the demands of the products are dependent on sales price, carbon emission and corporate social responsibility index. Assuming the cost and profit parameters, an expected profit function of the systems is formulated and maximized analytically. Finally, numerical examples are illustrated to justify the proposed model.  相似文献   
37.
This paper examines contrasting experiences of the United Kingdom in addressing high public debt to GDP ratios following major wars. A clear message is that interest rate / growth rate differentials were more important than primary budget surpluses for the different outcomes. The debt to GDP ratio fell very rapidly under financial repression following the Second World War but remained stubbornly high despite large budget surpluses with price deflation after the First World War. Implications for policymakers today are that averting price deflation is a high priority and that supply‐side policies that raise growth could play an important part in debt reduction.  相似文献   
38.
European power producers have a major influence on the EU ETS, given that both their CO2 emissions and their EUA (European Union Allowance) allocations account for more than half of the total volumes of the scheme. Fuel switching is often considered as the main short-term abatement measure under the EU ETS. It consists in substituting combined cycle gas turbines (CCGTs) for hard-coal plants in power generation. Thereby coal plants run for shorter periods, and CO2 emissions are reduced. This paper provides the first theoretical analysis of fuel switching, in a context where power plants involved are not equally efficient. We begin with a preliminary work using illustrative examples and sensitivity analyses, which enables us to observe how differences in the efficiency of power plants impact the cost of fuel switching, and how this is related to the level of switching effort. Based on this, we build a theoretical model taking into account the effect of differences in the efficiency of power plants involved in fuel switching. We also investigate the effect of the timing of fuel switching abatements, within the temporally defined environment of our dynamic model. Results demonstrate that the gas price and uncontrolled CO2 emissions act together on the carbon price. We show that the influence of the gas price on the carbon price depends on the level of uncontrolled CO2 emissions, due to heterogeneity of power plants that are used in the fuel switching process. Furthermore, we show that the time of occurrence of uncontrolled emissions matters so that shocks have a stronger impact when they occur in a period that is closed to the end of the phase.  相似文献   
39.
The nonperforming loans (NPLs) are co-generated by creating the profit in a bank, and this article build a joint production model to measure the reduction cost of nonperforming cost. By using a data set of China’s 13 commercial banks, the conclusions show that the reduction cost of NPLs is lower, which suggests that it is not a good choice for China’s commercial bank to hold the NPLs.  相似文献   
40.
The early stages of innovation involve high levels of uncertainty, leading to it being labelled as the “fuzzy-front end” (FFE). Although openness has been identified as pivotal to innovation performance in the open innovation literature, little effort has been put into exploring its role in the FFE. Specifically, this study examines ‘openness competence’ within the FFE–i.e., the ability of a FFE team to explore, gather and assimilate operant resources from external sources by means of external searches and inter-organisational partnerships. The aim is to investigate the impact of openness competence on front-end uncertainty reduction and service innovation success. Data were obtained from a survey of 122 IT-based service innovation projects implemented by IT service provider firms in Thailand. The results suggest that openness competence positively influences both the degree of uncertainty being reduced during the FFE and the overall success of service innovations. These findings offer several implications for research on open innovation and the FFE as well as encouragement to managers to apply a more open approach to the FFE of their service innovation projects.  相似文献   
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