基于LBPH算法的人脸识别算法研究与设计

人脸识别技术是一种根据人脸的特征信息进行身份判定的技术,此技术经过几十年的发展,由弱人工智能向强人工智能转化,论文提出了一种Python语言利用LBPH算法提取人脸特征、实现人脸识别的方法。     

A quantitative study of financing efficiency of low‐carbon companies: A three‐stage data envelopment analysis

This study set out to evaluate the financing efficiency of low‐carbon companies. Applying a three‐stage data envelopment analysis with the data from 85 listed companies in China's low‐carbon industries over the period 2011 to 2017, this study has found that the overall financing efficiency of low‐carbon companies was relatively high, and the pure technical efficiency was quite steady over the period. The overall financing efficiency of these low‐carbon companies on average tended to change with the scale efficiency. This study has also shown that the scale efficiency was the main constraint influencing the financing efficiency of low‐carbon companies in China over the period. Our results are robust and have significant implications for policy makers and corporate managers.     

水足迹视角下三江平原地区农业水土资源配置效率研究

[目的]三江平原地区是我国重要的商品粮基地,其农业水土资源相对丰富但水土资源配置效率不佳,亟待改善。[方法]运用投入导向型数据包络分析(DEA)方法,对水足迹视角下的三江平原地区农业水土资源配置效率进行评价。[结果]2015年,三江平原地区农业水土资源配置综合有效的地区仅占5%,总体来看,农业水土资源配置的技术效率略好于规模效率;水土资源投入冗余状况分析表明,友谊县、虎林市、宝清县、汤原县、富锦市、同江市等8个县、市辖区的农业水土资源投入合理,其他地区都存在不同程度的冗余现象;分作物来看,水稻生产的水土资源配置技术效率高于其他三大旱作。[结论]完善农业基础设施配套工程,提高水土资源配置的技术效率,是提高其规模效率,进而实现综合有效的关键。     

What determines the efficiency of Australian mining companies?

We examine the firm‐specific determinants of technical efficiency in Australian mining companies using data envelopment analysis (DEA). To do so, we employ panel data sourced from individual mining companies listed on the Australian Securities Exchange (ASX) over the period 2010–2014. To ensure valid statistical inference in the presence of serial correlation between DEA efficiency scores, we apply Simar and Wilson's two‐stage bootstrap method. We find that ownership concentration, firm size, firm age, product portfolio, product diversification and growth status significantly contribute to efficiency gains. However, other firm‐specific factors, such as capacity utilisation, financial risk and overseas operations appear to have limited impact on the technical efficiency of mining firms.     

SHIRKING,STANDARDS AND THE PROBABILITY OF DETECTION

By relaxing the common efficiency wage assumption of exogenous shirking detection probabilities, we demonstrate how standards and efficiency wages are related. In a more general setting where the probability of detection depends upon the equilibrium effort level of non‐shirkers, we show that the uniformly positive (negative) supply‐side relationship between wages (unemployment insurance) and effort is no longer guaranteed. Profit maximization on the part of the firm, however, ensures that effort will depend positively (negatively) on wages (unemployment insurance) in equilibrium.     

敦煌种业财务绩效评价研究

选择以农业上市公司敦煌种业为研究对象,以企业2014—2019年的报表数据为基础,采用功效系数法并以国务院国资委所编写的《企业绩效评价标准值》中国有企业绩效评价体系作为参考,构建对农业企业的财务指标评价体系,对敦煌种业2014-2019年企业财务指标的表现进行纵向分析,选择同行业中营业收入水平较高的北大荒进行横向对比,通过对比发现敦煌种业的问题主要体现在盈利能力和资产质量方面,对此提出了改进措施及建议。     

The rebound effect on energy efficiency improvements in China’s transportation sector: A CGE analysis

Energy use is becoming more efficient due to technological innovations. We focused on the transportation sector in China to develop a national multisector computable general equilibrium (CGE) model for analyzing the rebound effect from an improvement of 10% in the energy efficiency. We compared the size of the energy rebound effect at both the macroeconomic and sectoral levels in different transportation modal subsectors, namely rail, road, water, and air travel. The findings showed that the magnitude of the rebound effect varies across the transportation modes. This is particularly true for the air transportation sector, which has an economy-wide rebound effect of 30.1% and an own-sector rebound effect of 74.6% because of a sharp increase in the export demand for air transport services. We also quantitatively evaluated the contribution of energy efficiency improvement in the transportation sector to China’s economic growth and carbon reductions and found a positive dividend effect on the economy as well as the environment. The modeling results suggest that improving overall transportation energy efficiency by 10% generates an economy-wide welfare gain of approximately 29 billion yuan, while 19 billion yuan are attributable to a more efficient road transportation subsector. Furthermore, to offset the effects of these mode-specific rebound effects, we simulated the effectiveness of different policies and solutions. These included economic instruments in the form of energy, environmental, and carbon taxes, household transport consumption structure adjustments, and energy structure adjustments. This study revealed that combining these sustainable development policies offers opportunities for economy-wide multisectoral improvements in energy savings, emissions reduction, and economic benefits.     

Elasticity of substitution and technical efficiency: evidence from the US electricity generation

ABSTRACT

The implications of national or regional energy policies for technical efficiency and environmental outcomes in electricity generation depend on fossil fuel input substitution. This study uses state level data to examine fossil fuel (coal and natural gas) substitution in electricity generation under increased availability of natural gas in the United States. We observe that changes in elasticities of substitution from pre-2009 to post-2009 differ across states suggesting that the effects of increased availability of inexpensive natural gas on electricity generation have been spatially heterogeneous. We rely on the observed heterogeneity to assess the effects of fossil fuel input substitution on technical efficiency and CO₂ emissions. The results reveal that state level elasticity of substitution between natural gas and coal has a positive effect on technical efficiency and a negative effect on CO₂ emissions. Therefore, future policy design and analyses should reflect the implications for regional elasticities of fossil fuel substitution and associated environmental outcomes.     

The persistent institutional effect of liberal colonialism: evidence from China’s financial policies

ABSTRACT

The effect of liberal colonialism on the allocation of capital persists to this day. We exploit the colonial history of China during 1896-1911 with qualitative evidence to measure liberal colonialism. We document that liberal colonialism promotes the subsequent efficiency of financial policies on the capital allocation in 2004 through the quality of economic institutions.     

Estimating input-mix efficiency in a parametric framework: application to state-level agricultural data for the United States

ABSTRACT

This paper contributes to the productivity literature by demonstrating novel econometric methods to estimate input-mix efficiency (IME) in a parametric framework. Input-mix efficiency is defined as the potential improvement in productivity with change in input mix. Any change in input-mix (e.g., land to labou r ratio) will result in change in productivity. The advantage of this approach is that it does not require data on input prices to estimate the mix efficiency levels. A nonlinear input-aggregator function (e.g., Constant Elasticity of Substitution) is used to derive an expression for input-mix efficiency. Bayesian stochastic frontier is estimated for obtaining mix efficiency using US state-level agricultural data for the period 1960–2004. Significant variation in input-mix efficiency is noted across the states and regions, attributable to diverse topographic and geographic conditions. Furthermore, comparisons of allocative and mix efficiencies provide insightful policy implications. The production incentives such as taxes and subsidies could help farmers in adjusting their input mix in response to changes in input prices, which can affect the US agricultural productivity significantly. The proposed methodology can be extended by i) using flexible functional forms; ii) introducing various time- and region-varying input aggregators; and iii) defining more sophisticated weights for input aggregators.