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11.
Xiaojian Xu  Xiaoli Shang 《Metrika》2014,77(6):753-769
This article presents discussions on the optimal and robust designs for trigonometric regression models under different optimality criteria. First, we investigate the classical Q-optimal designs for estimating the response function in a full trigonometric regression model with a given order. The equivalencies of Q-, A-, and G-optimal designs for trigonometric regression in general are also articulated. Second, we study minimax designs and their implementation in the case of trigonometric approximation under Q-, A-, and D-optimality. Then, We indicate the existence of the symmetric designs that are D-optimal minimax designs for general trigonometric regression models, and prove the existence of the symmetric designs that are Q- or A-optimal minimax designs for two particular trigonometric regression models under certain conditions.  相似文献   
12.
就 业问题、环境污染以及从业人员研发能力下降已经成为制约软件外包承接城市发展的瓶颈问 题。文章运用DEA方法构建考虑非期望产出和非合意变量的软件外包承接效率评价模型,重 点比较不同模型下我国软件外包承接城市效率的差异,并引入Tobit回归分析软件外包承接 城市效率的驱动因素。研究发现:我国软件外包承接城市的投入产出组合在逐步优化,且东 部沿海城市的效率值明显优于中西部城市,其中大连市的效率值始终为1,处于生产的前沿 面。另外,人才竞争力对软件外包承接城市效率有显著的正向影响,信息技术基础设施竞争力与承接效率的关系呈显著负相关。  相似文献   
13.
Charitable foundations and government programmes should endeavour to allocate their limited resources to best serve their constituents. Yet, mathematical programming techniques are rarely used despite overwhelming evidence of their superiority in selecting projects that yield higher levels of total benefits. We present a novel ‘hybrid selection model’ that combines binary linear programming and heuristic rank-based models applied to two case studies. The first case focuses on providing services to women and shows a hybrid model would have selected the top three ‘signature’ projects and maintained an above-average overall project benefit while securing a 180% improvement in the number of projects funded, a 66% improvement in the number of women served and a 132% improvement in the total benefit achieved. In the second case, we apply the hybrid approach to data from the US government’s largest forest preservation programme and demonstrate that the hybrid approach could allow the programme to select up to 11 top-scoring projects while still achieving a 97% gain in the total overall benefit compared to their traditional method. These case studies show that the hybrid approach has the potential to be applied in a variety of settings and improve how foundations and programmes achieve their goals.  相似文献   
14.
This study employs the quantile regression model to examine the non‐monotonic impact of CEO stock‐based compensation on firm performance, using the data for U.S. non‐financial firms from 1993 to 2005. The results indicate that while the impact of CEO stock‐based pay on firm performance is positive for firms in the higher earnings quantile levels, the impact is negative for firms in the lower levels. In addition, the “V‐shaped” relationship between CEO stock‐based pay and firm performance satisfactorily explains the longstanding disagreement among earlier studies with regard to whether CEO stock‐based pay can enhance firm performance. Furthermore, the quantile‐varying pattern of the impact of stock‐based compensation on firm performance is robust after controlling for the industrial and yearly effects. It is also robust to the use of the pay‐for‐performance sensitivity as an alternative explanatory variable or the market‐based measure of performance as the dependent variable, or the consideration of the suspected endogenous problem between firm performance and stock‐based compensation.  相似文献   
15.
Canada and the United States have strong economic ties and form part of an integrated North American pork industry. Canada's pork industry is export-oriented, and the United States represents a key market for both live pigs and pork. Pork value chain stakeholders include input suppliers, pig producers, transportation companies, slaughter plants, wholesalers, and retailers. There are three overriding areas of concern for the Canadian pork industry with respect to potential impacts of the current pandemic (COVID-19). The first is Canada/US trade and the ability to continue exporting Canadian live pigs and pork to the United States. The second is labor and the impact of potential absenteeism on all sectors of the pork value chain. The third is global trade, because Canada's pork industry relies heavily on exporting pork to markets around the world.  相似文献   
16.
淮扬历史文化悠久,塑造了独特的饮食文化,其"精""雅""养"的饮食文化特质,成为中国饮食文化中的独特元素.在新的时代环境之下实现新的发展,这是淮扬饮食文化发展的内在需求.本文立足淮扬饮食文化特点,分析了其发展中面临的问题,并在此基础之上,从推动饮食文化创新、推动饮食产业发展、打造市场品牌影响力、实施"饮食+"措施等方面,阐述了淮扬饮食文化发展的路径.  相似文献   
17.
现有射频指纹识别研究主要集中于射频指纹产生及提取的通信机理,忽略了实际应用中信号采集数据的清洗筛分、识别算法模型的效率等工程性问题。为此,分析了卫星通信号的载波信息提取的原理与方法,并针对现有射频指纹方法的不足,围绕卫星信号识别领域,利用海量采集的射频指纹数据,深入研究基于自组织神经网络的射频指纹识别算法,提出了对应的算法模型,并与现有常见的无监督算法进行了比较。结果表明,所提方法可以取得更优的算法聚类效果和时间开销,可作为设计实现卫星频谱管理系统的基础。  相似文献   
18.
吕向阳  高尚 《价值工程》2011,30(24):147-149
简述了江苏省教育厅在本科品牌专业、特色专业验收时的验收标准。利用支持向量机建立了品牌专业、特色专业验收时的验收模型。通过实例,结果表明支持向量机比较精确和有效。  相似文献   
19.
本文对细胞穿透肽介导的凋亡素融合蛋白的研究现状及构建策略进行了交流报告。  相似文献   
20.
责任追究是企业实行党风廉政建设责任制的关键环节、核心问题.只有建立科学规范的运行机制,坚持事前防范,事中控制,和事后追究的原则,才能保证党风廉政建设责任制的真正落实.但从目前形式来看,很多单位和部门都存在责任追究不到位的情况,严重影响企业党风廉政建设的落实和效果.  相似文献   
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