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51.
公交都市是为了缓解小汽车的快速增长和交通拥堵问题所采取的城市交通战略.本文以湛江市为例,分析得出该市公交发展还存在着基础服务水平低、城市建设与公交发展不协调、公交优先战略未真正落实、智慧公交驱动力不足等问题,阻碍着城市与交通体系建设的有序发展.本文将智慧治理理念与公交都市创建在价值层面与技术层面进行结合,并借鉴新加...  相似文献   
52.
立足为优化国际营商环境贡献城市公交之智、发挥城市公交之力,以考核城市公交企业绩效目标为研究视角.本文在国内外研究基础之上,结合现行国家行业规范标准及实地调研结果,对标国际营商环境内涵特征构建城市公交KPI考核体系,并引入熵值法、层次分析法综合计算城市公交KPI考核指标权重,找出公交行业的关键事项或活动,为城市公交发展提...  相似文献   
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54.
Emissions of exhaust gases and particulate matter from a dual fuel marine engine using methanol as fuel with marine gasoil as pilot fuel have been examined for ...  相似文献   
55.
The importance of ocean waves parameters (propagation direction, mean period, significant wave height, etc.) is related to several aspects of a ships safety, efficiency in operation, routing, design, and maintenance. However, some available methods for obtaining those parameters have data limitations and inconvenient aspects. In severe weather conditions, an ocean-wave-field detector is necessary. This can provide two-dimensional ocean-wave-field information directly. Among other conventional methods, ship-borne wave radar has the ability to function as such a detector, and some researchers have tried to develop practical systems. A numerical approach using plan position indicator (PPI) images from conventional marine radars is proposed to retrieve valuable information from the ocean waves. A three-dimensional Fourier transform is applied to a set of consecutive radar PPI images to perform spectrum analysis. The removal of undesired elements in the spectrum is achieved by applying a hi-pass filter to remove static components, and by comparing the data with the expected dispersion shell to correct for nonocean-wave power. Numerical experiments under controlled conditions using simulated PPI images were performed through numerical simulations based on theoretical ocean-wave equations. The results include a comparison between the original wave parameters used in the simulation and the values retrieved from the spectrum analysis.  相似文献   
56.
The paper focuses on how trip time variability affects re-scheduling of daily activities. A delay in a trip or an early arrival can contribute to changes in the timing, location of the next activity, and to the deletion/addition of some activities. We propose the idea of using fuzzy logic rules to explain the effect of variability in travel time on the benefits perceived by an individual with the changes, and to model different actions that the individuals take in order to re-establish the steadiness of the existing timetable. The fuzzy model is used to handle the imprecision of the data which is unstructured text. The results show that large deviations in trip duration are more likely to induce significant changes in the timetable whereas small deviations are either ignored or translated into modified timing of the next activity. In choosing an action, greater importance is assigned to the flexibility of the following activity, to the magnitude of the trip time saving/delay, and to the duration of the next activity. Time savings are not favoured unless they can be readily transferred into additional activity time allocated to the next activity or to a new activity. The fuzzy rules based system is capable of predicting satisfactorily the strategy of coping with uncertainty in travel times and the satisfaction sensed with the change.  相似文献   
57.
Based on the volume constancy with equal flow-per-second and elastic sheet stability theory, a coupling relationship among lateral thickness difference, width-to-thickness ratio of cold rolling strip steel under ideal and actual working conditions, and shape is concluded according to the comprehensive influence principle of various factors on the critical instable shape analyzed in-depth. Firstly, the influence model under actual working condition is developed by referring to the basic relationship between lateral thickness difference and shape under ideal condition. The test results prove that for thin strips with thickness below 0.3 mm, their lateral thickness differences have significant effect on the shape. After then, the combined influence of lateral thickness difference and width-to-thickness ratio on the critical instable shape is concluded according to the elastic sheet stability model, with the synthetic effect of these three factors analyzed. Test data indicate that for cold rolling strip steel with width-to-thickness ratio above 3 000, the critical instability stress difference decreases significantly. Actual measurements are conducted on the lateral thickness differences of two rolls of typical strip manufactured by a sixhigh cold mill, with the influence law of lateral thickness variation and width-to-thickness ratio comprehensively investigated. It is demonstrated that during the production of ultrathin strip steel with different width-to-thickness ratios, the loading roll shapes should be fine adjusted according to the lateral thickness difference of input strips.Therefore, the variation of lateral thickness difference of output strips can meet the requirement of shape stability,so as to obtain fine shape.  相似文献   
58.
The back analysis of initial stress is usually based on measured stress values, but the measuring of initial stress demands substantial investment. Therefore, amounts of underground engineering have no measured initial stress data, such as tunneling engineering. Focusing on this problem, a new back analysis method which does not need measured initial stress data is developed. The fault is assumed to be caused by initial load, the displacement discontinuity method (DDM) which considered non-linear fault is adopted to establish a numerical model of the engineering site, and the multivariable regression analysis of the initial stress field around the faults is carried out based on the fault throw. The result shows that the initial stress field around the faults is disturbed significantly, stress concentration appears in the tip zone, the regressive fault throw matches the measured values well, and the regressive initial stress field is reliable.  相似文献   
59.
In this study, stated preference data is used to derive estimated values of commuting time (VOCT). Both spouses in two-earner households are individually making trade-offs between commuting time and wage; both with regard to their own commuting time and wage only, as well as when both their own commuting time and wage and their spouse’s commuting time and wage are simultaneously changed. Thus, we are able to compare how male spouses and female spouses value each other’s commuting time. When only ones own commuting time and wage are attributes, the empirical results show that the estimated VOCT is plausible with a tendency towards high values compared to other studies, and that VOCT does not differ significantly between men and women. When decisions affecting commuting time and wage of both spouses are analyzed, both spouses value the commuting time of the wife highest. Further analysis show that this result is driven by households where the man has the highest income. If VOCT were to be gender specific in policy implications, the value might be higher for women than for men in two-earner households.  相似文献   
60.
This paper is devoted to the problem of improving network performance to withstand incidents such as earthquakes, which have long-term adverse-effect upon the networks. A measure of link importance is presented based on consumers surplus. This measure is then used to define and solve a network improvement problem. Computational complexities are reduced by introducing an approximate measure of link importance which performs almost as good, and hence may be used for solving large scale problems. Several example networks are used to clarify the discussion numerically.  相似文献   
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