一种基于微波雷达回波信号的车型分类方法

车辆类型识别方法是智能交通系统的关键技术之一。利用深度学习的高维特征泛化学习能力，将改进的LeNet-5卷积神经网络用于基于交通微波雷达的大小车型分类识别。首先，以雷达触发前的N帧信号为基础，对雷达的回波信号进行分析并构建数据集；然后，分析LeNet-5卷积神经网络的特点；最后提出一种改进的LeNet-5卷积神经网络。实验结果表明，与传统的支持向量机方法相比，所提方法能够智能学习大小车的雷达时频信号特征，大小车型识别准确率达到97%以上，可为交通场景下的车型识别研究提供新的技术途径。     

基于卷积神经网络自编码器结构的空时分组传输方案

为提高现有端到端通信系统的泛化能力和可靠性，提出了一种基于卷积神经网络的空时分组码（Space-Time Block Coding，STBC）多输入多输出通信系统物理层方案。该方案将通信系统物理层表述、调制和解调过程联合起来形成端到端自编码器系统，引入多层一维卷积层，分别构建发射机和接收机，并扩展为多天线模式。为进一步提高系统可靠性，合理规划网络结构和参数，联合信号的调制和编码方案，优化了系统模型。仿真实验表明，针对瑞利相关衰落下多输入多输出（Multiple-Input Multiple-Output，MIMO）信道应用场景，训练模型可以实现传统STBC系统的误码性能，两发两收系统在发送端相关系数为0和0.9时分别优于传统系统0.5 dB和1 dB。此外，经过优化后的系统可获得采用卷积编码的性能改善效果，其两发两收不同工作方式优于传统1/2码率卷积编码STBC系统1~3 dB。     

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.     

Spatial and temporal analyses of potential land use conflict under the constraints of water resources in the middle reaches of the Heihe River

With the rapid urbanization in China, land resources are becoming increasingly scarce. Identifying and resolving land use conflict is essential for reasonably using land resources and achieving land sustainability. Taking the middle reaches of the Heihe River as an example, we included the constraints of local water resources to construct a multi-criteria evaluation system for assessing land use competitiveness in 2000 and 2015 based on land use, socio-economic, and nighttime light data. By comparing the competitiveness of cultivated land, construction land and ecological land, we then derived the spatiotemporal patterns of potential land use conflicts. Actual land use changes supported the hypothesis that land use tended to convert into the type with higher competitiveness at areas with intense conflict, which better indicated that our assessment model was effective. The results showed that the potential land use conflict was more acute in the central and northwest but weak in the southeast and northeast, and its pattern showed a significantly positive spatial autocorrelation. The conflict between cultivated land and construction land was most prominent and mainly occurred in the transitional zone from urban to rural areas. Rapid urban development and water shortage were the main causes of the potential land use conflict. Assessing land use multi-functions and making a tradeoff among ecological, economic, and social services will be an effective way to guide future land use to solve land use conflict. Our research provides scientific evidence for sustainable land use planning and management in the arid areas.     

内蒙古黄河干流跨盟市水权试点研究

为了全面总结内蒙古自治区水权试点工作,介绍了内蒙古黄河干流跨盟市水权试点过程中强化行业监管方面的一些做法,总结了试点过程中坚持问题导向、坚持两手发力、强化节水管理、创新体制机制的一些重要经验。     

Effects of consumer cohorts and age on meat expenditures in the United States

Meat demand is likely influenced by the birth cohort and age of the individual. In this study, we examine the demand for beef, pork, poultry, and other meat in the United States using the 1984–2012 Consumer Expenditure Survey and the almost ideal demand system with the incorporation of age, period, and cohort (APC) effects. We find that the model with APC effects performs better than the models without APC effects. The results indicate that cohorts born in earlier time periods are expected to purchase significantly less poultry compared to cohorts born in later time periods, when they are measured at the same age. Over the life cycle, purchase of poultry is expected to increase with age while the opposite is true for red meat. We also find that the own-price elasticity for beef is highest among the products examined, while the own-price elasticity for other meat is lowest and the inclusion of APC effects increases the absolute value of the own-price elasticities for beef, pork, and poultry, but reduces the own-price elasticity for other meat. Our forecasts indicate that the aggregate poultry purchase will continue to increase until 2022, while the aggregate purchase of red meat will slightly increase until 2017, but will either decrease or stay at same level from year 2017 to 2022.     

汇水系统绿地雨洪调蓄研究——以武汉港西汇水系统为例

绿地有一定的雨洪调蓄功能，雨洪状况下，如何在汇水系统尺度利用和保护绿地亟待研究。选取95处位于武汉港西汇水系统的地块，调研地块性质，利用ArcGIS提取不透水比例及平均坡度，并进行SWMM水文模型演算。通过实验性模拟结果的对比，得出汇水系统的绿地雨洪调蓄效率(λ＝0.13m3/m2)、汇水系统(g＝36%)和各类用地(g＝18%～47%)基于雨水调蓄理念下的最低绿地率，使汇水系统水文状况达到海绵城市建设标准。讨论了不同重现期下汇水系统的绿地雨洪调蓄效能，旨在完善绿地雨洪调蓄的研究方法、指标体系及利用与保护策略，为相关研究与实践提供借鉴。     

公司诉讼风险对审计决策的影响研究——基于异常审计费用和审计意见的证据

近年来上市公司诉讼风险不断攀升，对审计师决策行为的影响日益凸显。基于这一背景，系统探讨公司诉讼风险对审计决策的影响，分别研究公司诉讼风险对审计费用决策和审计意见决策的影响，并考察在诉讼风险冲击下审计费用决策和审计意见决策间的关系,同时结合我国制度背景，研究法律环境差异性对两种决策之间关系的影响。研究发现：公司诉讼风险越高，审计师收取正向异常审计费用的概率越高，出具非标准审计意见的可能性越大；审计费用策略和审计意见策略之间存在替代关系，即审计师倾向于在出具标准审计意见时收取正向异常审计费用作为风险补偿。进一步研究表明，在外部法律环境薄弱地区，审计费用决策和审计意见决策之间的替代关系更加显著。研究结论有助于合理解释和评价审计师的决策行为，对监管机构规范审计师的行为有着一定的启示意义。     

内部控制、僵尸企业与审计特征

以2010—2017年深沪两市全部A股上市公司为研究样本，分析僵尸企业的审计特征并探讨内部控制对两者关系的调节效应。研究发现：相比于非僵尸企业，僵尸企业具有倾向于支付更低的审计费用、更有可能收到非标意见和更有可能选择非高质量审计师进行审计的特征，同时，僵尸企业内部控制环境更差。进一步研究发现，更高的内部控制质量使得僵尸企业更有可能收到标准无保留的审计意见，但非僵尸企业审计收费更高且更有可能选择高质量审计师。基于产权性质的进一步研究发现：（1）国有僵尸企业支付更低的审计费用，且中央国企支付的审计费用更低；（2）民营僵尸企业更有可能收到非标审计意见；（3）民营僵尸企业和地方国有僵尸企业更有可能选择非高质量审计师进行审计，且地方国有僵尸企业倾向性更强。从公司治理角度研究僵尸企业的审计特征，为识别僵尸企业提供了经验证据。     

推动国有企业廉洁文化建设,以文化自信坚定理想信念

习近平总书记在党的十九大报告中指出:“没有高度的文化自信,没有文化繁荣兴盛,就没有中华民族伟大复兴。”廉洁文化建设是反腐倡廉工作的重要内容,是一项长期的、艰巨的、复杂的系统工程。论文结合福建省三钢(集团)有限责任公司在开展廉洁文化建设工作中的工作实践,对廉洁文化在企业发展中的重要意义、存在的问题及有效运用进行了分析与探讨,对推进廉洁文化进国企具有较为积极的指导意义。