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1.
基于质量功能展开方法的电动自行车设计优先度研究   总被引:2,自引:2,他引:0  
陈国强 《包装工程》2012,33(6):35-37
以质量功能展开方法在新产品开发中的应用为启示,从电动自行车设计角度,阐述了质量功能展开在确定该产品消费者需求与设计属性优先度的方法应用。首先,介绍了质量功能展开方法。进而通过电动自行车消费者需求、设计属性、质量功能展开矩阵分析,建立消费者需求与设计属性排序,从而该产品设计提供改善重点依据。  相似文献
2.
Research suggested that motorists’ right-of-way (ROW) violation in automobile-motorcycle gap-acceptance accidents at priority (i.e., stop-/yield-controlled) T-intersections has been a safety concern to motorcyclists. This study examines the characteristics of automobile-motorcycle gap-acceptance accidents that occurred at such locations. British Stats19 accident injury database during 1991-2005 are examined in detail. Automobile-motorcycle gap-acceptance accidents are classified into three crash scenarios: approach-turn, angle crossing, and angle merging crashes. Mixed (random parameters) logit models are estimated to investigate the contributory factors to motorists’ ROW violation in these three crash types. Crash features are also compared among gap-acceptance accidents and other crash scenarios. The methodological approach adopted allows for the individuals within the observations to have different parameter estimates as opposed to a single parameter representing all observations (i.e., accounts for unobserved heterogeneity potentially relating to roadway/environmental characteristics, and motorist behaviours). It was found that motorcycles’ ROW was more likely to be violated on non-built-up roads, and in diminished light conditions, with non-uniform effects across the observations. Elderly/female motorists appeared to be over-represented in gap-acceptance crashes. Implications of the findings are discussed.  相似文献
3.
Road safety performance indicators (SPI) have recently been proposed as a useful instrument in comparing countries on the performance of different risk aspects of their road safety system. In this respect, SPIs should be actionable, i.e. they should provide clear directions for policymakers about what action is needed and which priorities should be set in order to improve a country’s road safety level in the most efficient way. This paper aims at contributing to this issue by proposing a computational model based on data envelopment analysis (DEA). Based on the model output, the good and bad aspects of road safety are identified for each country. Moreover, targets and priorities for policy actions can be set. As our data set contains 21 European countries for which a separate, best possible model is constructed, a number of country-specific policy actions can be recommended. Conclusions are drawn regarding the following performance indicators: alcohol and drugs, speed, protective systems, vehicle, infrastructure and trauma management. For each country that performs relatively poor, a particular country will be assigned as a useful benchmark.  相似文献
4.
In this study, the safety of cyclists at unsignalized priority intersections within built-up areas is investigated. The study focuses on the link between the characteristics of priority intersection design and bicycle–motor vehicle (BMV) crashes. Across 540 intersections that are involved in the study, the police recorded 339 failure-to-yield crashes with cyclists in four years. These BMV crashes are classified into two types based on the movements of the involved motorists and cyclists:
  • • type I: through bicycle related collisions where the cyclist has right of way (i.e. bicycle on the priority road);
  • • type II: through motor vehicle related collisions where the motorist has right of way (i.e. motorist on the priority road).
The probability of each crash type was related to its relative flows and to independent variables using negative binomial regression. The results show that more type I crashes occur at intersections with two-way bicycle tracks, well marked, and reddish coloured bicycle crossings. Type I crashes are negatively related to the presence of raised bicycle crossings (e.g. on a speed hump) and other speed reducing measures. The accident probability is also decreased at intersections where the cycle track approaches are deflected between 2 and 5 m away from the main carriageway. No significant relationships are found between type II crashes and road factors such as the presence of a raised median.  相似文献
5.
This paper summarises findings on road safety performance and bus-involved accidents in Melbourne along roads where bus priority measures had been applied. Results from an empirical analysis of the accident types revealed significant reduction in the proportion of accidents involving buses hitting stationary objects and vehicles, which suggests the effect of bus priority in addressing manoeuvrability issues for buses. A mixed-effects negative binomial (MENB) regression and back-propagation neural network (BPNN) modelling of bus accidents considering wider influences on accident rates at a route section level also revealed significant safety benefits when bus priority is provided. Sensitivity analyses done on the BPNN model showed general agreement in the predicted accident frequency between both models. The slightly better performance recorded by the MENB model results suggests merits in adopting a mixed effects modelling approach for accident count prediction in practice given its capability to account for unobserved location and time-specific factors. A major implication of this research is that bus priority in Melbourne's context acts to improve road safety and should be a major consideration for road management agencies when implementing bus priority and road schemes.  相似文献
6.
Ulrich   《World Patent Information》2009,31(4):299-303
In 2001, a new ruling for the publication of patent applications at the United States Patent and Trademark Office came into effect. Since then, all applications which are also filed with foreign offices have to be published 18 months after the application date, in analogy to the ruling in Europe and Japan. This new regime replaces the former system where only granted patents were published. With about 70% of all applications the share of pre-grant publications of applications of US origin is quite high, allowing new types of statistical analysis. In particular, the investigations of time series based on priority years instead of grant years can thus be performed much more topically. On the one hand, a larger dataset for applications of US origin is available; on the other hand, the sample of applications from Asian countries is generally much larger at the US Patent Office than at the European Patent Office. Despite these new opportunities, searches at low levels of aggregation by codes of the International Patent Classification still have to be handled with care.  相似文献
7.
In the current quantification of fire probabilistic risk assessment (PRA), when components are damaged by a fire, the basic event values of the components become ‘true’ or one (1), which removes the basic events related to the components from the minimal cut sets, and which makes it difficult to calculate accurate component importance measures. A new method to accurately calculate an importance measure such as Fussell-Vesely in fire PRA is introduced in this paper. Also, a new quantification algorithm in the fire PRA model is proposed to support the new calculation method of the importance measures. The effectiveness of the new method in finding the importance measures is illustrated with an example of evaluating cables’ importance.  相似文献
8.
In this paper, a deteriorating cold standby repairable system consisting of two dissimilar components and one repairman is studied. For each component, assume that the successive working times form a decreasing geometric process while the consecutive repair times constitute an increasing geometric process, and component 1 has priority in use and repair. Under these assumptions, we consider a replacement policy N based on the number of repairs of component 1 under which the system is replaced when the number of repairs of component 1 reaches N. Our problem is to determine an optimal policy N* such that the average cost rate (i.e. the long-run average cost per unit time) of the system is minimized. The explicit equation of the average cost rate of the system is derived and the corresponding optimal replacement policy N* can be determined analytically or numerically. Finally, a numerical example with Weibull distribution is given to illustrate some theoretical results in this paper.  相似文献
9.
The Failure Mode, Effects and Criticality Analysis (FMECA) methodology is a widely recognized tool for the study and reliability analysis of a design or process. Many authors in the field have emphasized the usefulness of this particular method as well as its limitations. In particular, there are two main criticisms regarding the Risk Priority Number (RPN) method of calculation and the extreme difficulty in considering the variable of the corrective action cost in the analysis. The main scope of this work is to present a new integrated approach, named priority-cost FMECA (PC-FMECA), in order to exceed these limits. Making reference to a paper by Braglia [MAFMA: multi-attribute failure modes analysis. Int J Qual Reliab Manage 2000; 17(9)], this study proposes a method which allows for the calculation of a new RPN and the introduction of the concept of Profitability taking into consideration the corrective action cost. The study is divided in three fundamental phases: critical analysis of the FMECA model, proposal and development of the PC-FMECA and presentation of an implemented case study in the automotive field.  相似文献
10.
首先构建了一个制造/再制造集成物流网络:在该网络中,正向物流和逆向物流都是双层结构的,所有的物流设施均有能力限制,且假设再制造产品与新产品同质,都可以用来满足顾客的需求.在此基础上建立了一个混合整数非线性规划(MINLP)模型.然后提出了混合启发式算法求解.该算法用禁忌搜索法确定整型变量,用基于优先权的遗传算法解决多阶段运输问题.最后通过一个算例说明了模型和算法的有效性.  相似文献
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