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11.
支持向量机(Support Vector Machine,SVM)是建立在统计学习理论和结构风险最小化准则基础上的机器学习方法,该方法可以较好的解决以往很多学习方法的小样本、高维数、非线性和局部最小点等实际问题.本文利用支持向量机(SVM)回归理论和方法,建立基于核函数主成分支持向量机(Kernel Principal Component Analysis-Support Vector Machine,KPCA-SVM)回归模型,并用2000-2008年杭州市公路客运量为样本进行了预测,结果表明,KPCA-SVM模型具有较高的预测精度和可靠性,是一种有效的公路客运量预测方法.  相似文献   
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The concept of “inducing growth” is typically considered an adverse consequence of a project on the land use system. In certain instances, however, the desire to induce growth and foster land use change is a focus of land use policy. Such is the example of the Appalachian Highway Development System (AHDS) program initiated by the Appalachian Regional Commission (ARC) during the late 1960s. With the goal of providing highway infrastructure to improve assess to a geographically isolated and historically impoverished region, the ADHS has added nearly 3000 miles of highway to the Appalachian landscape. The degree to which highway investment has contributed to regional growth remains a controversial point and tractable methods to quickly assess landscape change given a project of this magnitude are elusive. In this paper a portion of the AHDS trending through southern Ohio is examined using data acquired from the Landsat series of satellites. Beginning with a pre-highway condition in 1976, a 26 year time horizon, concluding in 2002, was analyzed based on a post-classification change detection methodology. Results of this investigation revealed slight, yet significant, levels of urban expansion within a 10 km corridor along the path of AHDS Corridor D/State Route 32. Beyond this buffer zone the land use system evidenced more stability, suggesting that as distance increased from Corridor D/State Route 32, reduced accessibility also reduced the attractiveness of land for urban uses. Relating these results back to the infrastructure investment policies of the ARC demonstrates that growth did result from the construction of Corridor D and supports previous findings that land development based on highway construction is extremely time-sensitive.  相似文献   
13.
我国公路工程施工质量管理浅析   总被引:1,自引:0,他引:1  
我国每年的公路工程投资巨大,公路工程投资的质量管理是一个非常棘手的问题.文章根据公路工程建设的特点,分析了当前我国公路工程建设质量管理的问题,提出了解决的思路.  相似文献   
14.
The state of the nation’s infrastructure is the subject of widespread discussion and comment because it is thought to include many deteriorating and unsafe bridges. Ever since the terrorist attacks of 9/11, there has been increasing concern over the extent to which an attack on infrastructure could result in serious economic disruption. This research develops a model to analyze the economic consequences of an attack on a major element of the highway network. We add a freight network to a national multiregional economic impact model and make freight traffic flows endogenous. The use of a sub-national interstate model recognizes that most infrastructure planning is at the state level and most political leaders’ interest is local. We base our approach on the National Interstate Economic Model (NIEMO) and refer to an elaboration that we name Transportation network and the National Interstate Economic Model (TransNIEMO). The new model enables us to study the state-specific and industry-specific economic impacts of some significant changes in the nature of highway freight movements. We tested the model for selected freight movements in and out of California. The results are entirely plausible and encourage us to elaborate and test the model for hypothetical disruptions of freight traffic throughout the US.  相似文献   
15.
For many types of equipment whose maintenance requires skilled labor or whose random failure may have serious consequences, such as aircraft engines, medical equipment and others, customers generally prefer to entrust maintenance activities to the manufacturer or any of its representatives. The latter must, in turn, provide the customer with a maintenance program that is economically viable for both parties. In this study, the customer and the manufacturer agree on what follows regarding a non-self-announcing failure equipment whose state is only known through inspection: during the warranty period, the manufacturer inspects the equipment according to a specified schedule which he establishes taking into account that the costs incurred for inspections and replacements are supported by him during the warranty period. After the expiration of the warranty, inspections and replacements are performed by the manufacturer and billed to the customer. Moreover, penalties related to inactivity periods between failures and their detection are always supported by the manufacturer. The warranty is applicable to any equipment replaced during the validity period of the service contract. This type of contract generates a profit for the manufacturer. In this paper, an analytical model taking into account the commitments of both parties has been developed. The model allows generating the instants (x1, x2,…, xn) at which the inspections must be performed and the corresponding expected profit for the manufacturer while considering the warranty period offered on the market for similar equipment. An algorithm has also been developed to generate the inspection instants given the costs structure and the lifetime probability distribution of the equipment. In a context where business models argue for a greater implication of suppliers towards their customers, the proposed decision model may be relevant and very useful.  相似文献   
16.
This fictional prototype explores two of the future's major societal challenges: the delivery of healthcare to an increasingly ageing society; and the policing of a society, in which digital surveillance may predominate. It contrasts the author's vision of what life could be like in the United Kingdom in a decade's time (just as he contemplates retirement) with the simpler values of the 1980s, when he began his postgraduate career. The lyrics of the poignant 1982 Bruce Springsteen song, “Highway Patrolman” are used to bridge the epochs1. The prototype relocates the two main ‘middle-America’ characters, brothers Joe and Frank Roberts, in London in the year 2025. Much has already changed politically and socially in ‘Western societies’ in the intervening period up to 2012, driven by the inexorable advances of technology. As further scientific advances drive us to an anticipated paradigm change,2 one can only speculate on how society will advance, posing serious ethical dilemmas. Many of the changes will be positive. However, the story explores the potential negative consequences to the ageing population, in what appears to be a successful economy. Although somewhat pessimistic in outlook, a hopeful conclusion is that the ‘ties that bind’ will still predominate.  相似文献   
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何伟纲  裴俊 《特区经济》2008,(9):166-167
中国老龄化问题已是一个严峻的客观现实,本文在分析中国的老龄化五个突出的特点的基础上,阐述中国农村养老保障体系的六个方面。建立和完善社会养老保险制度,健全农村老年医疗保健机制,依法维护农村老龄人的合法权益,建立家庭养老与社会养老相结合的养老模式,关注农村老年人的精神生活,完善农村社会公共养老服务设施建设。  相似文献   
19.
The highway logo signing program has existed for over 20 years. Since its inception, most motorists have become accustomed to relying on these blue signs to provide information on services available at each highway exit. However, there is little, if any, literature that examines the program as an advertising source, and no formal literature that addresses the signing program from the perspective of the independent business owner. This paper provides service business owners with information about the highway logo signing program, and is directed toward independent owners who are considering the signing program as an advertising source. A five step process is described that owners can follow to first determine if the venue is viable, and then if the investment is value-added for them.  相似文献   
20.
Despite the extensive amount of data generated and stored during the maintenance capacity planning process, Maintenance, Repair, and Overhaul (MRO) organizations have yet to explore their full potential in forecasting the required capacity to face future and unprecedented maintenance interventions. This paper explores the integration of time series forecasting capabilities in a tool for maintenance capacity planning of complex product systems (CoPS), intended to value data that is routinely generated and stored, but often disregarded by MROs. State space formulations with multiplicative errors for the simple exponential smoothing (SES), Holt’s linear method (HLM), additive Holt-Winters (AHW), and multiplicative Holt-Winters (MHW) are assessed using real data, comprised of 171 maintenance projects collected from a major Portuguese aircraft MRO. A state space formulation of the MHW, selected using the bias-corrected Akaike information criterion (AICc), is integrated in a Decision Support System (DSS) for capacity planning with probabilistic inference capabilities and used to forecast the workload probability distribution of a future and unprecedent maintenance intervention. The developed tool is validated by comparing forecasted values with workloads of a particular maintenance intervention and with a model simulating current forecasting practices employed by MROs.  相似文献   
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