一种经验模式分解下的海杂波小目标检测方法

利用海杂波有效探测海上小目标是目前雷达探测领域的热点问题，具有重要的应用价值。鉴于海杂波是一种非线性非平稳性的雷达回波信号，充分发挥整体平均经验模式分解的优势，将海杂波分解为若干个不同尺度的独立分量。通过研究发现有目标时，分解出的前5个分量与未分解前信号的相关系数明显减小，因此提出了一种新的海杂波背景下的目标检测方法。通过实测和模拟的海杂波数据进行训练和测试，研究结果表明，该方法能有效地实现海杂波下目标的探测，性能优于经典时域下、分数阶傅里叶变换域下以及平均经验模式分解后的广义Hurst指数的目标检测方法。     

长江经济带中三角地区农业结构的分析与优化对策

[目的]从宏观、中观和微观3个层面深入分析长江经济带中三角地区湖北、湖南和江西3省的农业产业结构及其各产业差异性和相对优势及其竞争力。[方法]在宏观层面运用了传统的基尼系数分析3个省份历史发展上的地区经济水平差异,判断3个地区经济发展是否存在虹吸效应;从中观层面运用区位熵指数分析法分析区域农业产业结构,从农畜林渔等方面判断各区域产业专业化水平程度;从微观层面运用偏离—份额分析法(SSM)分离出3个地区的各部门产业的优势及其竞争力。[结果]区域内的经济差异变化呈不断增大的趋势,基尼系数不断扩大;湖北的种植业、渔业和农林牧渔服务业,湖南的种植业、林业、畜牧业和农林牧渔服务业,江西的林业、渔业都较中三角地区对应的子产业的区位熵指数高;江西木材和竹加工业和烟草业具有较大的产业竞争优势,湖北的茶叶、水产和瓜果疏菜产业优势明显,湖南地区农业产业综合优势主要在于烟草、水果、肉类以及木材和竹类加工业。[结论]通过比较地区农业产业竞争优势,提出发展地区产业特色,合理布局全域农业产业,提高农产品附加收益,稳固对结构优化的资金支持等对策建议。     

早晚航班对飞行员疲劳程度的影响

航空公司为了提高飞机利用率,导致早晚班的比重明显增加.由于飞行员生物节律的改变,致使其疲劳程度加深.为了保证飞行安全,减缓飞行疲劳,合理排班,需要对执行早晚班的飞行员的疲劳系数进行研究.通过对20名飞行员以及10名飞行学员进行电话访谈,了解到他们早晚班的疲劳程度,进而改进西南航空局可用机组疲劳系数的计算公式,优化了每名飞行员早晚班疲劳系数的计算公式.     

A Different Perspective on the Evolution of UK Income Inequality

This paper scrutinizes the conventional wisdom about trends in UK income inequality and also places contemporary inequality in a much longer historical perspective. We combine household survey and income tax data to provide better coverage of all income ranges from the bottom to the very top (and make our estimates available to other researchers). We make a case for studying distributions of income between tax units (i.e. not assuming the full income sharing that goes with the use of the household as the unit of analysis) for reasons of principle as well as data harmonization. We present evidence that income inequality in the UK is as least as high today as it was just before the start of World War 2.     

离差交易的实证研究与探讨

离差策略是一种对冲交易策略，它是利用股指期权和一揽子股票期权（或部分成分股构成的ETF期权）之间的隐含相关系数，获悉市场成分股期权和股指期权波动率高低的相对关系，再在成分股期权和股指期权建立相反的头寸。离差交易策略选择暴露的风险因子就是隐含相关系数，离差交易使用的是对冲的平价跨式期权交易。选用2006年5月18日至2014年7月17日前复权的沪深300股指、上证50指数和上证180指数作为样本，进行实证检验。虽然结果显著性较强，但不排除存在模型不稳定性以及由于数据不充分造成对相关系数及波动率估计的偏误。同时，离差交易使用的是对冲的平价跨式期权交易，所以组合暴露较小的Delta风险。若离差交易涉及较大的资金量时，则需要用标的资产对组合进行动态Delta中性对冲。     

基于K-S检验与距离相关分析的网络借贷信用评价指标体系构建

网络借贷作为一种新型互联网金融模式,提升了金融资源使用效率,缓解了小企业融资难的困局。构建合理的网络借贷信用评价指标体系,从而对网络借贷的潜在风险及时甄别与预防,对互联网金融健康持续发展意义重大。本文根据K-S检验与距离相关分析相结合,筛选对借款客户违约状态甄别能力强的指标,建立了网络借贷信用评价指标体系,通过P2P网络借贷(peer to peer lending,个人对个人借贷)平台LendingClub交易数据进行实证研究,结果表明:不仅借款金额、借款利率等借款标的特征对借贷者违约具有显著相关性,借款者年龄等个人特征、借款者年收入等财务特征以及借款者违约次数等信用特征均对借贷者违约风险产生显著影响。投资者在出借资金时,往往青睐于已婚、年龄适中、具有一定工作经历、历史违约次数较少的借款人。因此,风险监管部门应构建网络借贷违约风险评估模型,对P2P平台进行风险监测,同时建立关键信息共享机制,融合多源数据,明确审查范围,实现P2P网络借贷行业健康有序发展。     

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。     

Information transmission between large shareholders and stock volatility

Does information transmission between large shareholders exacerbate stock volatility or reduce stock volatility? In this study, based on the common shareholding data in the Chinese stock market from 2007 to 2017, we establish the shareholder’s coshareholding network, and use the weighted network clustering coefficient to measure the information transmission speed. Moreover, we investigate the impact of information transmission speed on stock volatility. The empirical results show that a nonlinear U-shaped relationship exists between information transmission speed and stock volatility. The findings are robust to the inclusion of other determinants of stock volatility identified in the literature. Finally, we verify the existence of private information interaction in the coshareholding network.     

Imperfect Accounting and Reporting Bias

Errors and bias are both inherent features of accounting. In theory, while errors discourage bias by lowering the value relevance of accounting, they can also facilitate bias by providing camouflage. Consistent with theory, we find a hump‐shaped relation between a firm's propensity to engage in intentional misstatement and the prevalence of unintentional misstatements in the firm's industry for the whole economy and a majority of the industries. The result is robust to using firms’ number of items in financial statements and exposure to complex accounting rules as alternative proxies for errors and to using the restatement amount in net income to quantify the magnitude of bias and errors. To directly test for the two effects of errors, we show that when errors are more prevalent, the market reacts less to firms’ earnings surprises and bias is more difficult to detect. Our results highlight the imperfectness of accounting, advance understanding of firms’ reporting incentives, and shed light on accounting standard setting.     

The trend of the Gini coefficient of China (1978–2010)

ABSTRACT

This study proposes a new approach to analyse the effects of an overlap term on the calculation of the overall Gini coefficient and estimates China’s Gini ratios since the adoption of the economic reform and open-door policies. A decomposition of the Chinese Gini coefficient for 1978–2010 reveals that the key factor contributing to income inequalities is the income disparity between rural and urban inhabitants. We further investigate the features of this income inequality between rural and urban areas and employ statistical approaches to evaluate the effects of urbanisation and rural-to-urban average income on nationwide income inequality. The results show that accelerating the pace of urbanisation is mainly responsible for decreasing China’s income disparity. Drawing on these results, we conclude with suggestions for related policies.