首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   187篇
  免费   3篇
  国内免费   4篇
财政金融   9篇
工业经济   22篇
计划管理   52篇
经济学   14篇
综合类   29篇
运输经济   5篇
旅游经济   13篇
贸易经济   22篇
农业经济   6篇
经济概况   22篇
  2024年   1篇
  2023年   4篇
  2022年   2篇
  2021年   5篇
  2020年   6篇
  2019年   3篇
  2018年   5篇
  2016年   5篇
  2015年   3篇
  2014年   12篇
  2013年   18篇
  2012年   19篇
  2011年   22篇
  2010年   16篇
  2009年   8篇
  2008年   7篇
  2007年   5篇
  2006年   18篇
  2005年   7篇
  2004年   7篇
  2003年   8篇
  2002年   2篇
  2001年   1篇
  1999年   3篇
  1997年   3篇
  1995年   2篇
  1993年   1篇
  1991年   1篇
排序方式: 共有194条查询结果,搜索用时 15 毫秒
71.
Despite the increasing number of accidents in process industry caused by human error, there are still too few efforts devoted to this area. This is mainly caused by people's tendency to overestimate human's capability in interacting with their working environment and moreover by the unavailability of reliable analysis methods. Because of the current lack of adequate methods, human factors (HF) analysis is not widely performed in process industry. Some HF techniques developed in the process industry were examined regarding their practical applicability and were unfortunately proved to be unsuitable for an elaborate HF analysis. Therefore, a new approach was developed, which provides a systematic way in performing a qualitative HF analysis to achieve a safer operation and decrease the number of human failure events. HF consideration during the design of a process plant is the key to minimize accidents caused by human error in process industry. Thus, an approach to incorporate HF into design phase is described in this article, which can help achieving a safer operation as early as possible with minimized costs. © 2009 American Institute of Chemical Engineers Process Saf Prog 2009  相似文献   
72.
本文主要阐述了模糊算子在遥感图像特征提取中的一般方法以及利用模糊算子对数据进行融合的应用等内容。  相似文献   
73.
目前,基于AHP法构建的供应商选择模型中,均未考虑实际决策时通常有多人参与,并且决策者会给出不同形式评价信息的情况。针对这一问题,将供应商选择视为一种不同形式偏好信息并存的群决策问题,结合AHP法,提出基于OWA算子的供应商选择模型。  相似文献   
74.
During the last three decades, integer‐valued autoregressive process of order p [or INAR(p)] based on different operators have been proposed as a natural, intuitive and maybe efficient model for integer‐valued time‐series data. However, this literature is surprisingly mute on the usefulness of the standard AR(p) process, which is otherwise meant for continuous‐valued time‐series data. In this paper, we attempt to explore the usefulness of the standard AR(p) model for obtaining coherent forecasting from integer‐valued time series. First, some advantages of this standard Box–Jenkins's type AR(p) process are discussed. We then carry out our some simulation experiments, which show the adequacy of the proposed method over the available alternatives. Our simulation results indicate that even when samples are generated from INAR(p) process, Box–Jenkins's model performs as good as the INAR(p) processes especially with respect to mean forecast. Two real data sets have been employed to study the expediency of the standard AR(p) model for integer‐valued time‐series data.  相似文献   
75.
基于局部线性估计方法研究误差具有自回归结构的变系数回归模型,讨论利用估计的残差和LASSO方法对误差部分进行定阶和估计的统计推断问题.通过蒙特卡洛模拟方法对比研究,揭示具有良好性质的局部多项式估计方法的有效性.  相似文献   
76.
在考虑物流服务商评价准则及限定条件的多样性和不确定性的前提下,在已有研究的基础上构建一种物流模式选择的模糊多目标决策模型,并且采用最大最小算子构建来属函数的方法对此模型进行规划求解.同时,还进一步提出了当考虑决策者对各个目标的偏好不同时,如何为各个目标赋予权重并求解,较好地保证了权重排序和隶属度排序具有较高的一致性,帮助决策者更好地选择出物流服务供应商.  相似文献   
77.
陈蓉 《价值工程》2014,(6):72-73
岩溶区公路路基稳定性研究的方法很多,本文采用区间模糊评判方法结合路基稳定性的特征对岩溶区公路的路基进行全面的分析,通过隶属度和权向量等方法的评判分析出适合岩溶区公路路基稳定性发展的方法,找出最终的测试结果和最终的使用方法。该方法使得岩溶区公路路基稳定性的评判更合理,更具有操作性。  相似文献   
78.
Despite persistent claims in the motor carrier industry of poorer safety performance of owner–operators, there is little empirical work directly comparing owner–operator safety performance to that of employee drivers. This study assesses the statistical significance of differences in the safety performance between owner–operators and employee drivers. This study also expands on previous driver focused safety models by examining how driver and carrier characteristics affect safety performance. Data for this study were derived from the Motor Carrier Management Information System (MCMIS), and the Commercial Driver’s License Information System (CDLIS) databases. Study results provide evidence that owner–operators are associated with more driver- and vehicle-out-of-service violations but experience lower crash rates than do employee drivers.  相似文献   
79.
This paper studies the differences in the impact of global tour operators on the management and performance of hotels in coastal and inland areas. The empirical analysis is based on a survey conducted in 2016 on 375 Spanish SMEs operating in the hotel industry. A multi-group comparison analysis was carried out using Partial Least Squares (PLS) structural modelling. This analysis reveals that dependence on global tour operators has a direct effect on the conditions under which hotel services are provided (room rates and quotas) both in coastal and inland areas. Nevertheless, the pressure from tour operators is significantly stronger on hotel SMEs located in coastal areas, where it has a negative effect on profitability, in spite of having a positive influence on firm growth (sales and employment).  相似文献   
80.
Under the “separation of three rights” policy, the impact of security of land operational rights on agricultural production efficiency has attracted much attention in recent years. Data envelopment analysis and mediation effect analysis were applied to 888 family farms run by new‐type agricultural operators from Songjiang to identify the mechanism of the effect of land operational rights security on agricultural production efficiency through long‐term investment. The results show that greater security of land operational rights generally increased agricultural production efficiency. Approximately 37.94 percent of the impact could be explained by long‐term investment. The results also indicate that significant heterogeneity exists in the effect of land operational rights security on agricultural production efficiency at various levels of the family farms’ efficiency distributions. It is suggested that government should legalize land operational rights and give them a status equal to those of households’ contractual rights and land ownership rights in China's future land tenure reform.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号